How to Remove Black Algae From Your Pool (8 Fast & Easy Steps)

Last Updated: June 18, 2021

Some sorts of algae will be simple to take away. Work in your pool pH ranges, throw in an algaecide, scrub the aspect and leap again in.

Unfortunately, eradicating black algae goes to be a way more intensive course of. Prepare to preserve the youngsters and the pets out of the pool for a number of days. While you might be working by means of the method of getting the pool swimmable once more, it isn’t secure for swimming. Here is our rundown of a quick and straightforward (as it may be) method of getting the black algae out of your pool.

Is It Safe to Swim If My Pool Has Black Algae?

This query has every thing to do with how a lot water you intend on ingesting whereas swimming. If you swim in a pool infested with black algae and swallow among the water, you may get very sick. As everyone knows, when youngsters swim within the pool, they have an inclination to drink a little bit of water. For this purpose, its essential to preserve youngsters out of the pool till the black algae leaves as nicely.

How Can I Be Sure It Is Black Algae I Have in My Pool?

Unlike yellow or green algae, black algae appears so much like mildew. The incontrovertible fact that it appears like mildew is what scares most pool house owners, and it ought to.

Just a few methods to know for positive that it’s a black algae infestation:

  • The algae will stick to the wall and doesn’t float across the pool
  • When you attempt to scrub it off its fairly tough
  • It appears to all be centralized in a tough space on the pool’s partitions (black algae likes to dig in deep)
  • Your canine took a swim on the seaside after which jumped within the pool!

Why Does My Pool Have Black Algae?

unused dirty pool algae

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On rare events, black algae can unfold by means of airborne spores, however the most definitely purpose is that somebody didn’t wash their bathing swimsuit after swimming in a pond, lake, or the ocean. Keep in thoughts that generally simply washing the swimsuits gained’t lower it. That kickboard, the goggles, the swim toys—all want to be adequately cleaned earlier than going again to the pool.

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Bathing fits going by means of the washer must be effective to use within the pool the subsequent time you swim. For pool toys, goggles, flippers, and so forth., use an answer of 1 tablespoon of bleach for one gallon of water to clear the tools. Anything much less is not going to cease the unfold of algae.

Since you might be most definitely studying this as a result of you have already got black algae, allow us to dive into how to repair this situation.

How to Remove Black Algae From Your Pool

Step 1: Cleaning Time

Clean every thing. No, it’s not enjoyable, and it’s going to take a while, however you want to clear every thing earlier than you make the issue worse. Clean all pool tools, filters, brushes, gloves it’s possible you’ll use, any pool toys, or floating thermometers that you simply had within the pool.

Use a half bleach half water answer to clear every thing, cleaning soap and water is not going to be sufficient. When every thing is sanitized, you might be prepared to transfer to the subsequent step.

Step 2: Test It

ph strip testing pool

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Now you want to run some assessments in your pool water to set up a baseline. Black algae love excessive PH, low chlorine, awful circulation, and filtration. It grows quickest in a heat pool on a sunny day. If your pool ranges are off in any method, alter them earlier than transferring to the subsequent step. Your pool chemical compounds want to be nicely balanced earlier than transferring to the subsequent step within the removing course of.

Step 3: Brush

Brush the pool totally—your entire pool, not simply the world with the black algae. If you’ve gotten a concrete pool, get a heavy-duty brush that can dig into the crevices. Black algae loves to get stronger by reaching itself down into the cracks of concrete. Now that it’s there, you want to get it out.

Spend quite a lot of time scrubbing, and though you might not be ready to scrub all of it off, just be sure you have 80-90 % of the algae faraway from the floor and within the water.

If you’ve gotten a vinyl liner in your pool, the brushing course of can turn into slightly extra difficult. Of course, a heavy-duty wire-bristle brush will spoil your liner and put you into a good worse scenario than your present one.

You might have to scrub longer than somebody with a concrete pool and thoroughly apply an applicable quantity of stress to get the algae loosened and launched into the water.

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In the areas the place you discover the best infestation of algae, you should use a chlorine pill to enable you to whereas scrubbing. It’s important to put on a glove whereas working with a chlorine pill as not to irritate your pores and skin. The chlorine pill ought to assist to get the work areas of the black algae loosened.

Once the algae are within the water, the shock remedy will work to begin killing it. If you skip the brushing step and go away the algae within the pool, you’ll not kill all the algae.

Step 4: Shocking

You could also be “shocked” by this, however the pool goes to want a extreme shock after this outbreak. A single dose of shock remedy shouldn’t be going to kill the black algae. We advocate doing a triple or quadruple shock remedy relying on how unhealthy your black algae outbreak is. For these with vinyl liners, be particularly cautious as shock remedies can generally discolor the liner in your pool.

Shocking the pool must be performed solely at night time. If the remedy is completed through the day, the solar will make the shock a lot much less efficient and trigger you to have to do it once more. Another trick of the commerce is to preserve all of these provides that you simply simply used to clear the pool in it when you shock it.

Guess what? That brush, these gloves, the pole—all of them have black algae on them from the work you simply accomplished. Treat this course of like a criminal offense scene—don’t go away any proof of that black algae!

Step 5: Run the Pump

A minimal of 24 hours.

The pool will most likely nonetheless not be clear, and also you shouldn’t be swimming. Keep the pump going for at least 24 hours earlier than transferring to the subsequent step.

Step 6: Brush It Again

pool brush / vacuum

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While the filter is working throughout these 24 hours, be certain to preserve brushing the pool diligently. At the very least, you’re going to need to brush it 4 instances, however six or eight can be even higher. We know that at this level within the course of, you might be prepared to snap the pole of the comb over your knee however belief us, you need the algae out and gone endlessly. Remember, when the Doctor mentioned to full your entire collection of antibiotics, the identical goes for black algae removing.

Step 7: More Cleaning (Unfortunately, We Aren’t Kidding)

After all of the scrubbing, cleansing, and surprising, it’s now time to clear the filter as soon as once more. All of the black algae that launched into the water can now be hiding within the filter. The last item you need is to let that develop and infest your pool once more. Due to the excessive ranges of chlorine that you simply used through the shock course of, a fast rinse of the filter must be sufficient. A easy backwash will doubtless work for many.

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After the filter cleansing is accomplished, deal with your pool with a normal algaecide. This will assist to not solely take away the black algae however another varieties that may very well be rising as nicely.

Step 8: Evaluate

For most individuals at this level, the pool will likely be again to regular, the water will likely be clear, and so long as the chlorine as returned to swimmable ranges, it may very well be time to leap again in.

Should you be one of many unfortunate ones and you’ll nonetheless see black algae within the pool, you’ll need to repeat some steps on this course of. Very merely, proceed the method of unpolluted, scrub, and shock. Pay shut consideration to how a lot shock you might be utilizing. After the preliminary triple or quadruple shock, you solely want to do a single or double shock.

If you occur to discover a small black algae situation beginning after you thought you had been within the clear, scrub it with a chlorine pill and shock the pool. Sometimes this may be sufficient to cease it earlier than it spreads.

However, if this doesn’t work, be certain to undergo your entire course of from begin to end once more.


After all is alleged and performed, this actually isn’t a tough course of. It is time consuming, irritating and can preserve you out of the pool for not less than a few days. The normal steps are:

Of course, we advocate following the whole course of we laid out above, however in the end, these three issues are the only and quickest method to take away black algae.

Next time somebody tries to rinse off in your pool after a day on the seaside, ensure you inform them concerning the brushing that will likely be concerned ought to they make that leap!

Keep your pool chemical ranges in examine, run your pool filter for 8-12 hours a day through the hottest days of the 12 months, and ensure your pH does not get too high. All of this stuff will preserve you from having to cope with this situation ever once more.

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