Why Do I Have a Green Swimming Pool?

There’s only one reason: pool algae. If it’s light green, the algae probably just started to take hold. But a deeper green means a bigger algae bloom problem.

Green algae growth happens when your sanitizer or chlorine levels are too low.  But before we dive in, if you want to stop your pool from turning green ever again, invest in our pool care video course. You’ll learn how to keep your pool maintenance and water chemistry in check so you never have to fight a green pool ever again.

Frustrated by adding chemicals and trying to keep your pool clear all the time?

We cut out all the confusion of pool maintenance in this easy-to-read illustrated ebook and video course. It'll help you save $100 right away on pool care!

Click Here to Learn More

How to Fix Green Pool Water Fast

Here’s our 5-step process for killing algae and clearing a swimming pool in less than a week. Make sure you follow every step to make sure you’re efficient as possible.

1. Brush the Pool Walls and Floor

Attach a pool brush to your telescopic pole and scrub the pool walls, floor, steps, and any other surface the algae may be clinging to. The goal is to get the algae floating in suspension in your pool water giving the chlorine a better chance to kill it.

Our Top Pick

Heavy Duty Round Pool Brush

The wide pool brush has 360 degrees of strong bristles to clean hard-to-reach pool surfaces fast, including steps, ladders, slides, diving boards, and tough corners/crevices in every type of pool. This one-of-a-kind pool brush eliminates back and hip pains associated with one-sided brushes.

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If you have a concrete pool, it’s best to use an algae brush for this task. Algae is tough, and will stubbornly cling to the pool’s surfaces, so a heavy-duty brush works better than soft nylon bristles to remove it.

2. Test The Alkalinity and pH Level

Using test strips or a liquid test kit, test the pH and alkalinity levels. Note the levels:

• The pH level should be between 7.4 and 7.6. It’s okay if it’s a bit lower since you’ll be shocking the water later which will raise the pH.
• The alkalinity level should be between 100 and 150 ppm (parts per million). Again, it’s okay if it’s a bit on the lower end.

If your pH and alkalinity are too high, bring them down at this stage. Start by adjusting your alkalinity (here’s our chemistry guide) and testing your water again to make sure you’re in the right range. Hopefully, by adjusting the alkalinity, it’ll put your pH in the right range too. But if not, adjust the pH as well (here’s our guide).

Note: Adjusting your pH and alkalinity at this stage will ensure the shock treatment will be as effective as possible. Having low or high levels may not help kill the algae. Also, testing the water could be the first step before brushing. If you’d rather test, then brush, go for it. It won’t affect the algae killing process.

Our Top Pick

Test Strips for Pools and Hot Tubs

Tests for 7 important chemistries in seconds: Total Hardness, Total Chlorine, Total Bromine, Free Chlorine, pH, Total Alkalinity, and Cyanuric Acid.

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3. Shock Your Pool with Chlorine to Kill Algae

This is the main event in clearing a green pool—killing the algae. Pool shock contains a high level of chlorine that will kill the algae and sanitize the pool. For the best results, use a shock that contains at least 70% available chlorine (calcium hypochlorite).

Our Top Pick

Calcium Hypochlorite Pool Shock (Cal-Hypo Shock)

This fast-acting, quick-dissolving swimming pool shock from DryTec kills bacteria, controls algae, and destroys organic contaminants in pools. It comes in easy-to-use 1-pound bags.

Use the entire contents of the bag when opened. If any granules settle to the bottom of the pool use brush to disperse them. Add the right dosage of this product during evening hours while the filter pump is running.

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Important: Even if you usually use non-chlorine shock, you must use chlorine shock to kill algae. And keep in mind it’s best to shock at night!

How much shock do you need to kill the algae in your pool? It depends on the color.

One pound (1 lb or 0.45 kg) of shock treats 10,000 gallons (37,854 L) of pool water. That’s a normal shock treatment if your pool wasn’t green. But since it is and depending on how much algae is in the water (see color chart above), you need to double, triple, or quadruple the dosage.

For example, if you have a 20,000-gallon (75,708 L) pool, and your water was dark green, you’d need 6 bags of shock. That’s a triple dose.

If you need more information on how to shock your pool the right way, here’s our pool shock guide, and the video below .

4. Run Your Pool Filter for 8 Hours (And Shock Again If Needed)

After you shock at night, your should run your filter system for at least 8 hours overnight. Even better, you should run your filter 24 hours a day until your pool is completely clear. This will help clear your pool faster.

Important: Make sure you backwash your filtration system when needed. If you need more help on when and how to backwash your sand, D.E., or cartridge filter, you can read our full guide here.

If the pool is still green or teal in the morning, hit it again with the same amount of shock the following night. And by the next morning, it should be cloudy blue. That’s the goal!

If your pool is cloudy blue, then you successfully killed all the algae in the water. Now you can use a pool clarifier if you want to clear it more quickly, but even if you do, be sure to run the filter for at least 24 hours to get the dead algae out of the water, and ensure the shock has fully dissipated.

Our Top Pick

Pool Water Clarifier by Swim University

Clears cloudy pool water by combining particles making it easier for your filter to remove. Let your filter do all the work! This fast-acting formula improves filter efficiency for the more effective removal of dead algae and organic debris. Apply clarifier directly to the pool. Great for all pools including inground, above ground, concrete, plaster, vinyl liner, and fiberglass. It's also compatible with salt water, mineral, ozone, and non-chlorine pool water. 

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5. More Water Testing and Adjust Pool Chemicals

When your green pool isn’t green anymore and you have cloudy blue or clear water, test it again. This time test for pH, alkalinity, calcium hardness, and your chlorine levels. Add chemicals as needed to balance things out.

Test it again to make sure everything’s as it should be, and you’re ready to enjoy your pool again.

How to Keep Pool Algae From Returning

Now that your pool’s clear again, you want to keep it that way. The number one method to do that is to ensure you maintain proper sanitizer levels. This entails testing your water frequently, at least once a week, but we like to test about every other day.

If you notice levels are a bit on the low side, add sanitizer immediately.

And if it will put your mind further at ease, you can add algaecide during regular water maintenance. But honestly, your best bet is just to stay on top of the sanitizer situation.

Our Top Pick

Pool Algaecide 60 (Copper-Free)

$40.89 ($1.28 / Fl Oz)

A copper-free algaecide to help prevent your pool from turning green.

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01/28/2023 08:22 am GMT

Do I Need to Worry About Pool Phosphates?

You may have heard pool pros or other pool owners say that to control algae, you need to control pool phosphates, and use phosphate remover to do so.

No, you don’t need to worry about phosphates, and no, you don’t need to use phosphate remover.

Trying to remove phosphates from any environment is like removing dust particles from the air. You will never, ever, ever be able to do it completely. The same is true for phosphates. They’re everywhere and in everything.

Yes, they’re a food source for algae. But to control pests in your vegetable garden, do you remove the vegetables? Of course not. You kill the pests. The same is true for algae.

Sanitize, sanitize, test, balance, and sanitize some more. And use the money you would’ve spent on phosphate remover on a nice pool float.

Frequently Asked Questions About Clearing a Green Pool

Opening your cover to a green pool may be disappointing. No, not “maybe.” It is. But never again will you feel defeated by algae now that you have the upper hand. All it takes is a little hard work and the right chemicals, and you can kick that algae to the curb — er, the pool deck.

How long does it take for a pool to clear up from green?

If you follow our method in this article, you can successfully kill all the algae in your pool in less than 5 days. We recommend adjusting your pH and alkalinity, double or triple shocking the pool at night with calcium hypochlorite shock, and running the filter system 24/7.

If you want to get the job done much faster (but with a little more manual labor), you can try our Fast Floc which will drop green water to the bottom of the pool so you can vacuum it out.

Our Top Pick

Fast Floc by Swim University

A fast-acting formula that drops cloudy water particles to the bottom of the pool so you can vacuum it out. Fast Floc will help you remove dead algae and non-living organic contaminants from your pool fast.

It's safe for all pools and filters including inground, above ground, concrete, plaster, fiberglass, vinyl liner, and more.

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Will chlorine clear up a green pool?

Yes! In fact, enough chlorine kills algae which causes green pool water. but it takes a large amount in the form of calcium hypochlorite super shock. Adding tablets in the skimmer or chlorinator will not clear up your pool. But you could also try using liquid chlorine instead of powdered shock as it mixes in the water faster. Just keep in mind that liquid chlorine is heavy to carry home from the store and to pour around your pool.

Will baking soda clear a green pool?

No. Baking soda will only raise your alkalinity and pH levels and this will not kill algae. Chlorine is what kills algae. But if you need help using baking soda to raise your alkalinity, read our full guide here.

Can you over shock a green pool?

No. The more chlorine shock you add to a green pool, the better chance it has to kill off all the algae. Follow the normal shock treatment based on the size of your pool and you can double, triple, or quadruple the dose to kill algae.

Will clarifier clear a green pool?

No. Pool clarifier binds particles together to be big enough for your filter to grab. If you have algae, it’s impossible for your filter to remove all of it. Instead, you need to kill it with chlorine. You can physically remove algae by using pool floc, which sinks the algae to the bottom of the pool, but it requires a lot of work to vacuum it out. Read our full pool algae guide here.

Happy Swimming!

The post How to Clear a Green Pool in 5 Days or Less appeared first on Swim University®.

Unfortunately, typical doses of chlorine will not kill pool algae. And running your pool filter will not eliminate algae spores.

To get rid of algae in your pool, follow these step-by-step deep cleaning procedures. Then avoid algae blooms in the future by using these smart pool algae prevention measures.

Watch the step-by-step video tutorial below or keep reading for the complete troubleshooting guide on how to get rid of algae in your pool.

What Causes Pool Algae?

Algae spores are everywhere. They can get into your pool through rain, dirt, and even wind. But those pervasive algae spores become a problem when they multiply in your pool water, turn into an algae bloom, or start growing on your pool walls. Low chlorine levels, improper pH levels, dirty filters, or pool circulation create the perfect conditions for algae growth. Algae can also be introduced by contaminated swimwear or toys that were used in a river, pond, lake, or ocean with algae.

Algae prevention is a lot easier than treating an existing large algae problem. That’s why it’s so important to keep your pool water balanced, clean your filter system and wash off any swimwear or toys that have been used in natural bodies of water.

What Are The Different Types Of Pool Algae?

Knowing what type of pool algae you have will help you treat it. First, figure out what color algae is in your pool. Then, keep reading for a complete step-by-step walkthrough on how to get rid of algae.

• Green pool algae is the most common and easiest algae to kill. However, this floating-green algae spreads quickly, clouding up your pool water and causing green slime on pool surfaces. Getting rid of green algae involves vacuuming and brushing your pool, then shocking and filtering your water. Green algae will vary in severity from teal green to dark, blackish green.
• Yellow pool algae, also called brown or mustard algae, is a rarer form of algae found in humid climates. It looks like globs of pollen or sand that cling to the shady corners of your pool. And unfortunately, it is chlorine-resistant. Killing mustard algae involves multiple rounds of brushing your pool surfaces and adding extra shock to your pool water. If you’re wondering if you have yellow algae, check out our guide on how to get rid of mustard algae in a pool.
• Black pool algae is actually a bacteria. Its roots dig into concrete surfaces, making it extremely tough to kill. Getting rid of black algae requires several rounds of deep cleaning, and it will grow back quickly if you aren’t thorough. If you’re wondering if you have black algae, check out our complete guide on how to diagnose and kill black algae in your pool.

How Do I Get Rid of Algae In My Pool FAST?

You can get rid of algae quickly by vacuuming and brushing your pool, balancing your pool’s water chemistry, and then shocking and filtering your pool water. Just be thorough as you clean your pool surfaces. If you leave behind even a small number of algae spores, it won’t be long before they regrow and bloom again.

1. Vacuum Your Pool Manually

Automatic or robotic pool cleaners aren’t well suited for cleaning algae. You’ll need to manually vacuum your pool on your filter’s Waste setting. This allows you to bypass your filter, preventing contaminated, algae-filled water from recirculating back into your pool.

When you vacuum your pool manually, pay special attention to areas with algae. And be sure to refill your pool’s water as you vacuum, maintaining your water level at least halfway up the skimmer. If you want to learn how to properly vacuum your pool, check out our guide on how to use a manual pool vacuum.

2. Brush Your Pool Walls and Floor

Scrubbing the algae off your pool walls helps chlorine get deeper into the remaining algae. It also loosens up contaminants so they can be killed and filtered out.

Using a stiff pool brush on a pole, brush the walls and floor of your pool. Pay special attention to corners, crevices, and shady areas where algae is usually worst. As you go, your water will become cloudy, obstructing your view, so brush the tougher spots first.

If you have a concrete or gunite pool, use a pool brush with stainless steel bristles to remove algae from your pool walls. Otherwise, we recommend using a nylon bristle pool brush:

Our Top Pick

Heavy Duty Round Pool Brush

The wide pool brush has 360 degrees of strong bristles to clean hard-to-reach pool surfaces fast, including steps, ladders, slides, diving boards, and tough corners/crevices in every type of pool. This one-of-a-kind pool brush eliminates back and hip pains associated with one-sided brushes.

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3. Test and Balance the Water

Use test strips, a digital kit, or a liquid test kit to test your alkalinity and pH. Balancing your water chemistry now ensures your sanitizer will be effective against the algae. High pH or low alkalinity will especially inhibit pool shock.

Our Top Pick

Complete Liquid Test Kit for Pools and Hot Tubs

A simple but effective liquid test kit for chlorine pools and hot tubs.

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4. Shock Your Swimming Pool

Adding shock to your pool super-chlorinates your water. And this extra dose of sanitizer will kill algae growth. The more serious your pool algae problem, the more shock you’ll need.

We recommend using calcium hypochlorite shock, or cal-hypo shock, as an effective algae treatment. Follow the package instructions to determine the dose for your pool size, then multiply that by two, three, or four depending on which type of algae you’ve got.

• Green Algae: Double dose of shock (x2)
• Yellow or Dark Green Algae: Triple dose of shock (x3)
• Black Algae: Quadruple dose of shock (x4)

Here is the type of cal-hypo shock we recommend:

Our Top Pick

Calcium Hypochlorite Pool Shock (Cal-Hypo Shock)

This fast-acting, quick-dissolving swimming pool shock from DryTec kills bacteria, controls algae, and destroys organic contaminants in pools. It comes in easy-to-use 1-pound bags.

Use the entire contents of the bag when opened. If any granules settle to the bottom of the pool use brush to disperse them. Add the right dosage of this product during evening hours while the filter pump is running.

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If you click this link and make a purchase, we earn a commission at no additional cost to you.

Remember to shock your pool at dusk or night. If you shock during the day, the sun will eat up most of the chlorine before it has a chance to kill the algae. And put your cleaning equipment, like your vacuum head or pool brush, in the shallow end of your pool so your tools will get sanitized while the shock is in the water.

Be sure to run your filter for eight hours or overnight to circulate the shock. If there’s still a significant amount of algae in your pool, repeat the brushing and shocking process again.

If you need help shocking your pool, check out our guide on how to use pool shock.

5. Filter Out The Pool Algae

After your shock treatment kills the algae, it’ll turn your water a cloudy blue. Don’t panic! That’s just dead algae.

When algae dies, it turns from green to gray and the dead, gray algae particles need to be filtered out. Run your filter continuously for a minimum of eight hours or until the water clears up. And you can use our water clarifier to speed up the process.

Our Top Pick

Pool Water Clarifier by Swim University

Clears cloudy pool water by combining particles making it easier for your filter to remove. Let your filter do all the work! This fast-acting formula improves filter efficiency for the more effective removal of dead algae and organic debris. Apply clarifier directly to the pool. Great for all pools including inground, above ground, concrete, plaster, vinyl liner, and fiberglass. It's also compatible with salt water, mineral, ozone, and non-chlorine pool water. 

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If you click this link and make a purchase, we earn a commission at no additional cost to you.

6. Test Your Pool Water Again

Make sure your water chemical levels are balanced and your chlorine is back to normal before anyone gets back into the water. Adjust your alkalinity, pH, and chlorine levels as needed. You may also want to test your cyanuric acid and calcium hardness levels since you’ve removed water from your pool and replaced it with fresh water.

7. Clean Your Pool Filter

Your filter just processed a lot of contaminated water. And the last thing you want is your dirty filter slowly adding microscopic algae spores back into your pool. Deep clean your filter cartridges by soaking them in diluted muriatic acid, or by replacing them entirely. If you have a sand or D.E. filter, now’s the time to backwash.

Want to stop your pool from ever turning green again? Check out our pool care video course. You’ll learn how to keep your pool chemistry in check so you never have to deal with algae outbreaks in the future.

Frustrated by adding chemicals and trying to keep your pool clear all the time?

We cut out all the confusion of pool maintenance in this easy-to-read illustrated ebook and video course. It'll help you save $100 right away on pool care!

Click Here to Learn More

Can You Use Algaecide to Get Rid of Pool Algae?

Technically, you can use an algaecide to kill algae. But we don’t recommend using it to get rid of a large algae problem. Algaecide is very expensive compared to chlorine. And it can introduce a lot of copper to your pool water. However, algaecide is effective for early-stage algae growth, small amounts of algae, or as a preventive measure. For more information on using algaecide, check out our article The Truth About Using Pool Algaecide.

Algaecide is also handy for killing off lingering algae after you’ve cleaned your pool. Once you’re done vacuuming, brushing, and shocking your pool, wait for your chlorine levels to fall below 5 ppm. Then add a dose of algaecide. Brush your pool to loosen any last bits of algae you can’t see. The algaecide will help kill remaining algae particles before they’re filtered out.

Here’s the algaecide we recommend. Add this as a final step in the algae clean up process or as a preventative measure in your pool:

Our Top Pick

Pool Algaecide 60 (Copper-Free)

$40.89 ($1.28 / Fl Oz)

A copper-free algaecide to help prevent your pool from turning green.

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01/28/2023 08:22 am GMT

Can You Use Pool Flocculant to Remove Pool Algae?

Yes, you can use pool flocculant to treat the early stages of algae growth. This additive bonds to floating algae particles, making it easier to vacuum them out of your pool. But if you have anything more serious than a mild green algae problem, we recommend you follow the full cleaning plan.

Here is the pool flocculant we recommend for milder algae problems:

Our Top Pick

Fast Floc by Swim University

A fast-acting formula that drops cloudy water particles to the bottom of the pool so you can vacuum it out. Fast Floc will help you remove dead algae and non-living organic contaminants from your pool fast.

It's safe for all pools and filters including inground, above ground, concrete, plaster, fiberglass, vinyl liner, and more.

Buy Now From Swim University

If you click this link and make a purchase, we earn a commission at no additional cost to you.

Here’s how to use pool flocculant to get rid of early-stage algae:

1. If you have a multiport valve on your filter, shut off your pump and turn the valve to Recirculate or Recycle. This will mix the floc around without filtering the water. If you need help understanding your multiport valve, check out our guide on how to use a multiport valve.
2. Add the recommended dosage of flocculant to your pool.
3. Circulate your water for two hours, then shut off your pump and let it sit overnight. The floc will bind to the algae, then settle on the pool floor.
4. Turn the multiport valve set to Waste so dirty water doesn’t blast back into your pool through your return lines.
5. Hook up your backwash hose to the Backwash/Waste port. Direct your wastewater appropriately.
6. Vacuum your pool. Work slowly to make sure you get all the thick sediment off the bottom. If the water gets too cloudy, you may need to stop and allow the particles to settle again before continuing to vacuum.
7. Add water while you’re vacuuming to maintain your pool’s water level.
8. Double shock immediately after vacuuming to eliminate any remaining algae. You may also want to brush the pool sides and floor before shocking.
9. Run your filter until the water clears.

How to Prevent Algae in Your Pool

Following these basic pool maintenance principles will help prevent future algae issues.

• Test and balance your water once a week, after rainstorms, or after heavy use (like pool parties). Adjust your alkalinity, pH, and chlorine levels as needed
• Shock your pool once a week during peak pool season
• Run your pump 8 to 12 hours per day to fully circulate your water
• Clean or backwash your filter regularly
• Wash and sanitize your swimwear, pool equipment, floats, and toys before introducing them back into your pools
• Add flocculant or algaecide if you notice the early stages of algae growth

Frequently Asked Questions about Algae in Pools

Looking for more help with algae in your pool? Here are some common questions and answers.

Can you swim in a pool with algae?

Technically yes, but it’s not recommended. Algae itself is not harmful to swimmers, but pools with lots of algae can contain harmful bacteria and pathogens like E-coli. And cloudy water caused by algae can be a hazard if swimmers can’t see the bottom of the pool. Avoid swimming in a pool that isn’t properly sanitized and cleaned.

How do you treat algae in saltwater pools?

Getting rid of algae in a saltwater pool is exactly the same process as a traditionally chlorinated pool. Remember, a saltwater pool is a chlorine pool. You are just adding salt instead of a chemical to generate chlorine. Like a traditional chlorine pool, you’ll want to use calcium hypochlorite shock, also known as cal-hypo shock. For more information, check out our guide on how to remove algae from a saltwater pool.

Does phosphate remover kill algae in pools?

Phosphate removers work by cutting off the nutrient source for algae. The more phosphates in the water, the more there is for algae to consume. But phosphate removers won’t solve any underlying water chemistry issues, like low chlorine or improper pH levels. If you keep your water sanitized with chlorine, algaecide, and the occasional pool shock, you won’t need a phosphate remover. Be sure to check out our complete guide on phosphates in pool water.

Does shock kill algae in pools?

Yes, shock is the key ingredient to killing algae in pools. Shock raises the free chlorine levels in your pool water to the point where contaminants like algae die off. Depending on the severity of your algae growth, you’ll need to add 2-4 doses of shock. And it’s normal to see cloudy water after killing algae with shock. The water should clear up after you run your filter. Just be sure to vacuum and brush your pool before using shock. This helps remove and loosen up large amounts of algae.

Here’s the type of shock we recommend:

Our Top Pick

Calcium Hypochlorite Pool Shock (Cal-Hypo Shock)

This fast-acting, quick-dissolving swimming pool shock from DryTec kills bacteria, controls algae, and destroys organic contaminants in pools. It comes in easy-to-use 1-pound bags.

Use the entire contents of the bag when opened. If any granules settle to the bottom of the pool use brush to disperse them. Add the right dosage of this product during evening hours while the filter pump is running.

Buy Now On Amazon Buy on InTheSwim.com

If you click this link and make a purchase, we earn a commission at no additional cost to you.

Need More Pool Maintenance Help?

• Download our free Pool Care Cheat Sheet. It’s a free, easy-to-use guide to help you keep track of taking care of your pool.
• Subscribe to our Swim University YouTube Channel. We publish free video tutorials throughout the pool season.
• Check out our Pool Care Course. You’ll get 30+ step-by-step videos and a step-by-step downloadable guide with everything you need to know about pool maintenance.

The post The Smart Way to Kill Algae in Your Pool Quickly appeared first on Swim University®.

Why Do You Have Black Algae in Your Pool?

Simple. Someone swam in a natural body of water like a river, pond, lake, or the ocean, didn’t wash their swimwear afterward, and then wore that same swimwear into your pool.

Maybe that was you, and you did remember to wash your swimwear in between, but forgot about that inner tube you used to float down the river, and then tossed it into your pool unwashed. You just put out the welcome mat for black algae in your pool.

It’s less likely, but black algae can also enter your pool via airborne spores.

Now what? Well, the first step to getting rid of black algae is understanding what it is, because guess what? It’s not algae at all.

What is Black Algae?

True algae is an aquatic plant belonging to a group that includes everything from single-celled organisms to seaweed. This is why when you think of algae, you think of it as being something green—it usually is.

Like most plants, green algae contains chlorophyll, the pigment that gives it its green color. Chlorophyll is also the substance that allows a plant to perform photosynthesis, the process by which the plant uses light to synthesize food from carbon dioxide and water.

What we call black algae is actually a bacteria. Specifically, a cyanobacteria, which refers to blue-green algae, hence the cyan part of its name.

So if black algae is cyanobacteria, which is blue-green in color, why is it black?

Cyanobacteria contains chlorophyll, which contributes to its blue-green color. But it can also contain other water-soluble pigments that, when combined with the blue-green pigment, make the bacteria appear black.

Is Black Algae Harmful?

In a word, yes. It can be. The emphasis of this danger is usually placed on blue-green algae, though.

Cyanobacteria blooms in natural bodies of water can kill other organisms and animals that live in that water by blocking sunlight and hoarding oxygen and other nutrients. This isn’t something you need to worry about in your pool.

But cyanobacteria also make cyanotoxins, which are among the most powerful natural poisons in the world. They can make you, your pets, and any other animals that might find their way into your pool sick.

Just swimming in water infected with black algae can be enough to cause illness. But the probability and severity of illness is increased if you accidentally drink infected water.

If you have black algae in your pool, and your kids accidentally swallow pool water while they’re horsing around, they could experience anything from nausea and stomach cramps to liver damage. And have you ever seen your dog take a drink from the pool? They’re in just as much danger of becoming sick if the water is infected with black algae.

You must be able to identify black algae as soon as it appears, and take immediate action to get rid of it.

How to Recognize Black Algae in Your Pool

So first, it’s not really algae, but cyanobacteria. And what does it look like? Mold. No wonder this stuff is so hard to kill! It’s like a chameleon!

Seriously, if you notice something starting to form on your pool’s surfaces, and it looks like a bunch of tiny black dots or big clumps of mold, you may have black algae in your pool. And because it’s cyanobacteria, those clumps may actually look more blue-green than black.

Also, black algae seldom forms in pools with fiberglass or vinyl liners. It’s more at home in concrete, plaster, or gunite pools because they’re porous surfaces the organism can really latch onto, and even “grow roots” past the surface.

A few other ways to recognize black algae in your pool:

• The black or blue-green spots and clumps have raised heads, and are attached to the pool’s surface. They don’t float freely in the water.
• It establishes itself in areas where the pool surface is rough and it can really grab hold.
• It doesn’t brush off the wall easily with your regular pool brush. Sometimes, even with an algae brush.
• It can be scraped off the pool’s surface, even though it may take some elbow grease. Pool stains cannot be scraped off.
• You may find it even if you’re vigilant about keeping your pool water balanced, sanitized, and filtered. Again, it enters your pool from external natural water sources.

Recognizing it means you can take the right steps to get rid of it because treating black algae like green algae won’t work. You need to get out the big guns.

If you’re having trouble with pool algae of any color, invest in the pool care video course. You’ll learn how to properly take care of your pool so stuff like this doesn’t happen ever again. You won’t waste your time and money fighting algae problems that are easy to prevent with the techniques in the course.

Frustrated by adding chemicals and trying to keep your pool clear all the time?

We cut out all the confusion of pool maintenance in this easy-to-read illustrated ebook and video course. It'll help you save $100 right away on pool care!

Click Here to Learn More

How To Kill Black Algae

Plain green algae is pretty easy to kill because it’s a plant, and anyone without a green thumb can attest that you can kill a plant just by looking at it the wrong way. Or is that just us?

Anyway, the fact that black algae in your pool is actually bacteria is what makes it so hardy and hard to kill. And you thought that was just a movie.

The good news is, it’s not impossible to kill. It will only take a little more effort and persistence on your part.

Before you begin, gather the supplies you’ll need:

• backwash hose (if necessary)
• filter cleaner
• filter sand (if needed)
• DE powder (if needed)
• replacement filter cartridge (if needed)
• test strips or liquid test kit
• algae brush
• chemical-resistant gloves
• safety goggles
• chlorine tablets
• chlorine tablet holder
• telescoping pole
• calcium hypochlorite shock

Make sure you stretch before you start, because you’re going to get quite a workout.

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1. Clean the Filter

If you have black algae in your pool, you have black algae in your filter. If there’s only a small amount of black algae in the pool, you can probably get away with backwashing your pool filter (for sand or DE filters), or rinsing the filter cartridge.

If the algae problem is extensive, use a filter cleaner rather than just plain water.

With as difficult as black algae is to get rid of, though, you may also want to consider completely replacing the filter medium or cartridge. Start over fresh so you know for sure there’s not one speck of black algae lurking in your filter, waiting to reinfect your pool after you’ve gone to all the trouble to get rid of it.

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2. Test and Balance the Water

Ensuring your pool water levels are where they need to be helps determine how much how much pool shock to use when you get to that step, and will help the shock kill the black algae in your pool.

You can use test strips or a liquid test kit. You don’t need to concern yourself with levels for things like calcium hardness right now. Focus on alkalinity, pH, and sanitizer, and shoot for optimal levels.

• alkalinity: 100 ppm to 150 ppm, with 125 ppm being ideal
• pH: 7.4 to 7.6
• chlorine: 1 ppm to 3 ppm (or the proper range for whatever sanitizer you use)

If those levels are out of whack, adjust them before proceeding.

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3. Brush the Pool

Wait, maybe we didn’t make that clear. You’ll need to BRUSH the pool. Brush it like you’ve never brushed it before. We’re talking Korean body scrub intensity and thoroughness.

Your usual, everyday pool brush won’t do. You need a stainless-steel-bristled brush to get into those cracks and crevices and really dig that black algae out of its hiding places. That is, unless you have a fiberglass or vinyl liner. In that case, use a nylon-bristled brush, and about twice as much elbow grease.

Brushing the black algae loosens it from the pool’s surfaces and puts it into the water where the shock will be able to kill it.

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Algae Brush with Stainless Steel Bristles

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4. Scrub the Black Algae Spots

No matter how well you just brushed your pool, you’ll probably still see some spots where the black algae just didn’t come loose. Now you need to get up close and personal.

You can use a putty knife, a pumice stone, or even a hand-held wire brush to scrub the remaining black algae off the pool’s surfaces. We like to use chlorine tablets because now only do they offer a scrubbing surface, you’re also applying chlorine directly, which can start killing the bacteria while you scrub.

1. Put on your chemical-resistant gloves and protective eyewear.
2. Break a 3-inch chlorine tablet in half.
3. Hold it firmly, and scrub the black algae with the broken edge.

For those spots you can’t reach:

1. Place one half of the tablet in a chlorine tablet holder with the broken portion facing outward.
2. Attach the holder to your telescoping pole.
3. Scrub the black algae spots you’re unable to reach by hand.

Don’t worry if you don’t get every speck of black algae off the pool surfaces because next you’re going to …

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5. Brush the Pool Again!

Didn’t we say you’d need to stretch before you started? If your arms are cramping now, take a break, eat a banana to give your muscles some potassium, and then get back to work. You’re not done yet.

6. Quadruple Shock the Pool

Did we mention black algae is difficult to kill? A regular dose of shock won’t be nearly enough to get rid of it. Now that you’ve brushed as much gunk off your pool’s surfaces as you can, you need to kill all that nasty stuff floating in the water.

Follow the manufacturer’s instructions to determine the correct dose for your pool’s volume, then multiply that by four. Not sure how much water your pool holds? You can use our pool calculator to figure it out.

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Even if you don’t normally use it, we highly recommend using calcium hypochlorite shock to kill the black algae in your pool. Nothing else will work as well.

Tip: Place all your pool maintenance equipment—the algae brush, the tablet holder, the leaf skimmer if you’ve used it recently, everything—in the shallow end of the pool to sanitize it during the shocking process.

Important: Remember to shock your pool at dusk or night. If you shock during the day, the sun will eat up most of the chlorine before it has a chance to kill the algae.

Our Top Pick

Calcium Hypochlorite Pool Shock (Cal-Hypo Shock)

This fast-acting, quick-dissolving swimming pool shock from DryTec kills bacteria, controls algae, and destroys organic contaminants in pools. It comes in easy-to-use 1-pound bags.

Use the entire contents of the bag when opened. If any granules settle to the bottom of the pool use brush to disperse them. Add the right dosage of this product during evening hours while the filter pump is running.

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7. Run the Pump

To get the shock dispersed so it can do its job and kill all the black algae in your pool, run the pump for 24 hours. You may come back to cloudy water, but that’s perfectly normal.

“But wait!” you say. “Isn’t this going to put black algae right back into the filter I just cleaned a while ago?!”

Yes. But don’t worry because thanks to the shock, it will be dying. And—spoiler alert!—you’re going to clean the filter a second time, though not as rigorously.

8. Brush the Pool

Déjà vu! During that 24-hour period while the chlorine level in the water is so high, brush the surfaces at least two more times—preferably three or four times—to get any remaining black algae off the walls and floor of your pool.

9. Clean the Filter

The first time you cleaned the filter was to get any live bacteria out of the filter. When you ran the pump after shocking, the filter probably accumulated bits of black algae—like it was supposed to—but it would have been dying thanks to the superchlorination treatment.

So this time, no need to replace any medium or cartridge. You can simply backwash your sand or DE filter, or rinse the cartridge. But to be on the safe side, because you can’t be too careful when it comes to dealing with black algae in your pool, we recommend using a filter cleaner.

10. Shock the Pool Again, If Necessary

If, after a quadruple shocking, running the pump for 24 hours, brushing the pool multiple times, and cleaning the filter a second time, you still see any remnants of black algae in your pool, shock it again.

Only this time, use double the dose. Then get that brush ready. You know what’s coming.

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01/27/2023 04:08 pm GMT

11. Run the Pump Again

This time, you could probably get away with running it for 8 or 12 hours, but again, we’re talking about black algae, so we recommend running it for another 24 hours.

12. Brush the Pool

By now, you should be able to beat Sylvester Stallone in an arm wrestling competition. But this really is the only way to get all of that nasty bacteria off your pool’s surfaces. Once it gets rooted in there, it’s more difficult to remove than any other type of algae, mold, or bacteria that may befall your pool.

If you want to make sure it doesn’t come back, do not, under any circumstances, skip the brushing.

13. Test and Balance the Pool Water

After all that work, your pool should now be free of black algae. Test the water, and then add the appropriate chemicals as needed to bring all the levels back to where they should be.

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14. Keep an Eye Out for Stragglers

Over the next few days (weeks, really), keep a close eye on your pool for any signs of black algae returning. It’s possible that, even with all that shocking and brushing, you may have missed a teeny-tiny bit that will start to grow again. We’re talking about bacteria, remember. It’s microscopic.

If you do see a small spot reappear, brush it off, scrub the spot with a broken chlorine tablet, and then give your pool a normal dose of shock.

After all that, we’re betting you don’t ever want to see the smallest spot of black algae in your pool again, right? So make sure you do everything you can to keep it out.

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How To Prevent Black Algae from Invading Your Pool

The first line of defense is to always, always wash your swimsuits, aquatic shoes, toys, anything you may have used in a natural body of water before you allow it to even touch your pool.

And just rinsing isn’t enough. Everything must be washed. It’s fine to put swimwear through your washing machine, but pool toys must be scrubbed with a solution of one tablespoon of bleach per gallon of water to not only clean, but sanitize them. You can also use a spray cleaner that contains bleach. Either way, rinse everything thoroughly before putting it back in the pool.

After those preventive measures, keeping your pool properly balanced and sanitized is the next step to keeping all forms of pool algae from growing.

• Keep your alkalinity, pH, and sanitizer levels in the recommended ranges at all times.
• Run your pump and filter for 8 to 12 hours a day, every day, all season long.
• Keep your pool clean by regularly vacuuming and brushing it.
• Shock your pool at least every week. More often if you’re using it more often, or more people are swimming in it, or both.
• Keep your pool equipment clean, including skimmers, hoses, ladders, steps, the diving board, slides, solar blankets and your safety cover.
• Keep your pool accessories clean, including pool toys, floats, drink holders, floating speakers, and anything else that touches your pool water.
• Require anyone who uses your pool to rinse off first. If they refuse, show them these instructions and tell them that if they cause another case of black algae in your pool, they’ll be doing all the brushing.

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01/28/2023 07:15 am GMT

You Can See Clearly Now, the Algae’s Gone!

Whew! We’re tired after just putting all this down, so we can imagine how exhausted you must be! It’ll be worth it, though, to kill the black algae in your pool and keep it from returning.

More importantly, you’ll be keeping your family and pets safe, and maintaining a pool that’s clean, sanitary, and fun to use without any worries.

Happy Swimming!

The post How to Kill Black Algae in Your Pool appeared first on Swim University®.

Just don’t wait around. That algae can grow out of control in no time, making algae removal even more difficult. By following a few simple steps, applying some elbow grease, and putting some chemicals and equipment to good use, you can destroy that algae bloom by tomorrow and keep it from coming back.

What Turned Your Salt Water Pool Green?

One day your pool is crystal clear. The next, it looks … different. Your once-sparkling pool is now milky, green, mustard-yellow, or even black. It looks like a swamp monster will come crawling out of there any minute. What the heck happened, and how did this muck get into your pool?

Pool algae comes from some surprising sources—like you and your family. Really. Swimmers can carry algae spores in their bathing suits from other places they went swimming. It may also stick to pool floats, swim vests, even your pool cleaning equipment. Have you ever felt little slimy patches on your floats? That could be the start of your next algae bloom.

Algae Types and Impostors

Before you can treat them effectively, you need to know the different types of algae, and common algae imposters. If you don’t treat it aggressively enough, you’ll wind up with a rebound algae bloom in no time. And, of course, more swamp monsters.

Green Algae

Chlorophyta is a cyanobacteria that gets its green color from chlorophyll, the chemical that lends its familiar hue to all green plants. Green algae reproduce in every manner a chlorophyta possibly can, which can be explained with lots of sciencey words. The takeaway is that it’s a problem that multiplies rapidly in your pool, especially when you don’t have enough free chlorine in the water. Your pool may turn from a bit cloudy to an obvious green color in one day.

Yellow Algae

It’s commonly called mustard algae, but you definitely don’t want to put this stuff on a hot dog. You’ll know you have yellow algae if you see debris that looks like pollen or clumpy sand gathered in the corners and on the floor of your pool.

Black Algae

This is another type of cyanobacteria, but this black version is not true algae. It appears as black spots along rough surfaces inside your pool. Although it may seem innocuous at first, don’t be fooled. So-called black algae digs its roots deep into your pool walls, making it incredibly resistant to chlorine.

Pink Slime

You may not realize that pink sludge collecting around your pool components is not actually algae, but a bacteria. No one wants to swim in bacterial soup, so as soon as you see pink slime forming, you must act quickly to treat it.

Salt Water Chlorination

If you’re new to caring for a salt water pool, you may not know the water is actually chlorinated. In fact, it has (ideally) the same amount of free chlorine as any regular pool. The difference lies in how the sanitizer is administered to your pool water.

With a salt water system, you put salt into your pool instead of chlorine. Your salt chlorine generator then zaps (super-technical term) the saline solution (salty water), turning the salt into hypochlorous acid (HClO) and sodium hypochlorite (NaClO), the compound commonly known as chlorine.

Because the electrolysis (zapping) process occurs as the salt water passes through the chlorinator, the chlorine is added slowly and steadily around the clock. Your chlorinator won’t ever provide a massive dose of pure chlorine to your pool all at once, so the water is softer and gentler for swimmers’ skin, hair, and eyes.

The downside is it can also make it easier for algae to grow if you let your pool chemistry slip even a little.

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Super Chlorination

Most salt water chlorinators have the option to boost chlorine output to 100 percent for 24 hours. Doing so increases the chlorine output, immediately raising the free chlorine concentration in your pool water.

This mode is meant to be used whenever your pool experiences a heavy bather load (lots of swimmers), rain increases the water volume, you’ve added more water after evaporation, or your water is just looking a little cloudy. You’ll also super chlorinate weekly, just as you would add shock to a regular chlorine pool to eliminate chloramines and bather-introduced contaminants.

But the boost mode isn’t strong enough to address algae problems.

Launch Your Attack

Because your chlorinator’s boost mode can’t deliver the goods, you’ve got to do the work yourself with some standard pool equipment and chemicals you should have on hand at all times.

A Little Elbow Grease

Using an algae brush, scrub as much of your pool walls and floor as you can reach. The more algae you can free from the walls, the better. Any residue can be better treated by the chlorine after you’ve scrubbed off the top layers.

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Algae Brush with Stainless Steel Bristles

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Suck It Up, Buttercup

Manually vacuum your pool, being as thorough as possible. All that algae debris is floating around, waiting to be sucked out. Be sure to vacuum to waste, if you can, so you’re not sending the algae right back into your pool. You may need to add some water to your pool afterward to get it back up to the ideal level.

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Pool Maintenance Is Like A Bicycle …

… to keep your balance, you must keep testing your pool water. Wait, is that the right quote? Regardless, test and balance your pool water after vacuuming. You’ll want to get the pH and alkalinity just right before you add that mega-dose of chlorine.

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Double, Triple, or Quadruple Shock

Use the dosing chart on your shock to determine the recommended dose for your pool size, and then adjust the treatment depending on the type of algae in your salt water pool:

Just a little green algae: Double the usual shock treatment.
A lot of dark green algae: Triple shock.
Mustard algae: This stuff can withstand a lot of chlorine, so triple shock to kill it all the way dead.
Black algae: This one’s really hard to kill. Quadruple shock.
Pink slime: Remember, it’s bacteria, not really algae, so treat it like you’d treat any bacterial problem: quadruple shock.

Note: Use calcium hypochlorite shock to safely shock the algae in your salt water pool into oblivion without adding unnecessary chemicals to the water.

Our Top Pick

Calcium Hypochlorite Pool Shock (Cal-Hypo Shock)

This fast-acting, quick-dissolving swimming pool shock from DryTec kills bacteria, controls algae, and destroys organic contaminants in pools. It comes in easy-to-use 1-pound bags.

Use the entire contents of the bag when opened. If any granules settle to the bottom of the pool use brush to disperse them. Add the right dosage of this product during evening hours while the filter pump is running.

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Panning for Algae

The high dose of chlorine and dead algae spores suspended in your water will make it look really cloudy right after shocking. That’s completely normal. Fortunately, you don’t have skim all of it out by hand.

Run your filtration system overnight (or for at least eight hours) until your pool water isn’t cloudy anymore. If your water is still cloudy after eight hours of filtering, you can add a dose of pool water clarifier, then continue running the filter until the water clears.

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Pool Water Clarifier by Swim University

Clears cloudy pool water by combining particles making it easier for your filter to remove. Let your filter do all the work! This fast-acting formula improves filter efficiency for the more effective removal of dead algae and organic debris. Apply clarifier directly to the pool. Great for all pools including inground, above ground, concrete, plaster, vinyl liner, and fiberglass. It's also compatible with salt water, mineral, ozone, and non-chlorine pool water. 

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Test Again

Now your water looks great, but you need to make sure the sanitizer levels have returned to a safe level before anyone dives in. Grab your test strips and check it out. If your water chemistry needs any tweaking at all, do it now.

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Test Strips for Pools and Hot Tubs

Tests for 7 important chemistries in seconds: Total Hardness, Total Chlorine, Total Bromine, Free Chlorine, pH, Total Alkalinity, and Cyanuric Acid.

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About That Filter

Your filter has been working overtime to get rid of algae spores. Just to be sure it doesn’t allow any old algae to wash back through your return lines, take it out and deep clean it with muriatic acid.

Better yet, whether it’s near time for a filter replacement or not, install a new one. If you use a diatomaceous earth or sand filter, you’ll need to backwash to waste, then determine whether it’s time to replace your filter medium.

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Prevention Methods

In addition to using an algaecide as part of your water care routine, you can do a few more things to help prevent the growth of algae in your salt water pool.

• Shower before getting in the pool to help remove any residual algae spores on swimwear. Showers also limit swimmer-introduced contaminants such as lotions and shampoos, which cause your sanitizer to work overtime, limiting its ability to kill any algae that finds its way to your pool.
• Wash swimsuits after every use to remove algae spores, especially if you’ve been in a public pool or natural body of water which is more likely to have algae spores. If you’ve only been swimming at home, a good rinse between swims should be sufficient.
• Clean pool toys and equipment between uses. You can wipe down floats and other pool items with diluted bleach to kill algae spores and mildew. Rinse well so the bleach doesn’t degrade the integrity of your floats.
• Balance your water chemistry weekly. We can’t overstate how important this is.
• Use your chlorinator’s boost mode weekly (or more often if needed) to keep free chlorine levels where they should be. If your pool is being used heavily, it’s not overkill to test the water every afternoon or evening, then use boost overnight if needed.

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01/27/2023 09:39 pm GMT

Keep Those Swamp Monsters at Bay

If you thought you wouldn’t have any water problems with a salt water pool, you’re not alone. Unfortunately, despite the many positive aspects of salt water pool ownership, they’re not naturally resistant to algae.

Now that you’re armed with the best methods for killing that algae, act swiftly to stop it in its tracks. Keep it from coming back with algaecide and good prevention practices, and you won’t have to worry about those swamp monsters ruining your backyard fun.

Happy Swimming!

The post How to Fix a Green Salt Water Pool appeared first on Swim University®.

What is Mustard Pool Algae?

Its verdant cousin, green algae, is slimy and tends to cling to walls or form gross, blobby “patties” in your pool. But mustard algae is a horse (or at least a plant) of a different color.

Commonly found in southern climes, and more rarely in northern ones, mustard algae is often mistaken for sand, dirt, or a stain in your pool. It’s a member of a microbe family known as xanthophytes. These algae are chlorine resistant, and more persistent than an Amway salesman in a stuck elevator.

Mustard algae likes to attach itself to pool walls and other items, which is a problem since it can also survive outside your swimming pool. This nasty little customer can piggyback on pool equipment, toys, floats, and even your bathing suits. You’ll definitely want to have the disinfectant handy if you even suspect your pool has an infestation of mustard algae.

Kill Mustard Algae in Ten Easy Steps

If a dose of the yellows is giving you a serious case of the blues, there’s no need to panic. Following a few simple steps will help you banish the bloom and regain your swimming sanity.

1. Machine Wash Your Bathing Suits

A trip through the laundry will kill off any mustard algae clinging to life on the fabric of your suits. Regular or color-safe bleach, as appropriate, can give you added peace of mind.

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01/28/2023 12:33 am GMT

2. Clean Your Pool Toys, Floats, Etc.

Using a clean cloth and a chlorine-based cleaner (but not straight-up bleach), give all your pool toys and other accessories a thorough wipe-down.

Why not just reach for the bleach? Using full-strength bleach could damage some plastics and rubber items, so it’s best to stick with a multipurpose cleaner that’ll kill mustard algae without destroying your possessions.

If all you have on hand is bleach, dilute it in a one part bleach to ten parts water solution before applying it to any surfaces.

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01/27/2023 09:39 pm GMT

3. Move Your Pool Equipment to the Shallow End

Gather up all your maintenance equipment, including all your hoses and poles, and place them in the shallow end of your pool, if it has one. If you have stuff on hand that might be infected with mustard algae, but is too awkward or bulky to sanitize by hand, go ahead and add it to the pool too.

Consolidating all your gear in your pool will make it easy to disinfect everything when you add pool shock for sanitizing.

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4. Brush and Vacuum out the Mustard Algae

Removal is the first step to a fully sanitized pool, and removing mustard algae begins with a good brushing. Use an algae brush to loosen the algae and make it easier to vacuum out.

Note: Mustard algae can live in your pool’s filter, so switch it to the “waste” setting rather than “backwash” before you fire up the vacuum.

Manually vacuum the pool, taking care to get as much of the mustard algae as possible.

Finally, add fresh water to replace the water lost to vacuuming.

Our Top Pick

Concrete Pool Flexible Vacuum Head

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5. Test and Balance Your Pool Water

When you have too little sanitizer or your water chemistry is otherwise out of whack, algae can thrive. Time for some pool water testing! Grab some test strips and have at it.

After you’ve taken a reading, adjust your water’s alkalinity and pH—in that order—as needed to reach a total alkalinity of 100 parts per million (ppm) to 150 ppm and a pH level of 7.4 to 7.6. Properly balanced water will help your pool shock work more effectively and make sure it (ahem) cuts the mustard.

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6. Brush Your Pool—Again

And you thought the dentist was a nag. Grab your trusty algae brush and give the entire pool a good scrubbing.

This’ll help break up the remaining algae and get it into suspension. When it’s free-floating in the water, your pool shock of choice will have a much easier time attacking and destroying it.

Our Top Pick

Algae Brush with Stainless Steel Bristles

Perfect for getting rid of algae. For concrete pools only!

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7. Triple-Shock Your Swimming Pool

No, we don’t mean embarrassing the pool in public or telling it you never loved it. Just like regular old boring green algae, mustard algae is susceptible to the cleansing might of pool shock, especially at high concentrations.

Use three pounds of pool shock for every 10,000 gallons of pool water. To maximize your shock’s efficiency, add it to your pool at dusk or during the night. Leave your filter and pump running 24 hours a day until the algae is gone.

Our Top Pick

Calcium Hypochlorite Pool Shock (Cal-Hypo Shock)

This fast-acting, quick-dissolving swimming pool shock from DryTec kills bacteria, controls algae, and destroys organic contaminants in pools. It comes in easy-to-use 1-pound bags.

Use the entire contents of the bag when opened. If any granules settle to the bottom of the pool use brush to disperse them. Add the right dosage of this product during evening hours while the filter pump is running.

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8. Keep On Brushin’ and Balancin’

Channel your inner Marcia Brady and brush like a fiend in the days following the triple-shock. You’ll discourage the mustard algae from clinging to your pool and keep it in suspension for faster annihilation.

Adjust your chlorine levels as necessary to keep its killing power high. Make sure you test your pH and alkalinity levels frequently, adjusting as necessary to keep them in the optimal ranges.

9. Shock Again for Safety

After a few days, any remaining mustard algae will be lulled into a false sense of safety. They might think they’ve escaped, despite your mad brushing and shocking and testing. They might even be a little cocky. That’s when you strike with the fury of a thousand angry gods. Ha! That’ll teach ’em!

If you don’t have the fury of a thousand angry gods lying around at home, try another dose of shock, at regular strength. One pound of shock for every 10,000 gallons will help ensure your pool’s truly sanitized. And remember, be sure to shock at dusk or after nightfall.

10. Test and Confirm Your Pool is Algae-Free

After the final shock treatment, test your water chemistry. If the balance is right, and your water appears to be clear, congrats! You’ve sent mustard algae packing.

You can remove your pool equipment and anything else you had soaking in the shocked pool too.

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01/27/2023 07:26 pm GMT

How to Keep Mustard Algae Away

Having tossed the mustardy interlopers out on their tiny yellow ears, you can keep them from coming back with a few simple precautions.

• Practice smart water chemistry. Keep your pH, alkalinity and sanitizer levels in the correct ranges at all times.
• Keep to a schedule. Run your pump and filter 8–12 hours a day, all season long. Keep your pool clean with regular brushing and vacuuming.
• Shock like it’s your job.Once a week, every week, add one pound of shock for every 10,000 gallons of pool water. Shock at dusk or in the evening.
• Clean everything. Yes, all of it. Pool toys, floats, ladders, steps, diving boards, slides, solar blankets, and covers can all harbor algae if left damp and dirty. A quick spray and wipe with a chlorine-based cleaner will go a long way toward protecting you and your pool from algae attacks.

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01/28/2023 07:15 am GMT

One Clean Pool—Hold the Mustard

Why struggle with condiment-colored crud when you could be soaking up the sun? Catch up on your pool care and leave the mustard in the kitchen with the hot dogs.

With thorough sanitizing and regular care, you can kill mustard algae, prevent its return, and relish a stress-free swimming pool, all season long.

Happy Swimming!

The post How to Get Rid of Mustard Algae in a Pool appeared first on Swim University®.