How to Get Rid of Dead Algae In Your Pool

Written by Michael Dean
August 25, 2023

dead algae in a swimming pool

You’re not alone if you’re dealing with dead algae in your pool. Imagine getting ready to take a dip, but your pool water looks murky and uninviting because of lingering algae, YUCK! The good news? While dead algae is unsightly, it is much easier to get rid of than live algae blooms. 

In this article, I will go over my handy step-by-step guide for getting rid of dead algae in your pool, answer some common questions, and review the causes of dead algae accumulation.


Main Takeaways

  • Skimming, brushing, and vacuuming are crucial to prevent and remove dead algae.
  • Keeping your pool filter clean helps remove dead algae and debris effectively. 
  • Balanced water chemistry discourages algae growth and promotes a healthy swimming environment.
  • Consistent pool care, including circulation and debris removal, is your best defense against dead algae buildup.

Step-by-Step: How to Get Rid of Dead Algae In Your Pool

Check out this step-by-step guide to effectively eliminate dead algae from your pool and restore your pool to its crystal-clear state! But first, what do you need?

Supplies Checklist

  • Pool net
  • Telescopic pole
  • Skimmer net
  • Pool brush
  • Pool vacuum
  • Filter element cleaner (for cartridge filter)
  • Bucket (for cartridge filter)
  • Pool water testing kit

Step 1: Skim and Remove Debris

To kick off the process, gather your supplies for surface cleanup. Get your trusty skimmer net attached to a telescopic pole. Start by removing larger debris from the pool’s surface, such as clumps of dead algae, leaves, and other contaminants. Doing this prevents the dead algae from decomposing further in your water.

Step 2: Brush the Pool

Now, grab your pool brush and scrub the walls, floor, and corners of your pool. Doing this will dislodge the dead algae while also facilitating improved water circulation so that your filter can do its job of clearing the water. Be thorough!

Step 3: Vacuum the Pool

To vacuum your pool manually, attach the pool vacuum head to a telescopic pole. Then, connect the vacuum head to your pool’s skimmer and start vacuuming! Just as with the brush, make sure to cover every surface of the pool and be as thorough as possible. After vacuuming once, you may want to wait for the dead algae to settle on the bottom and vacuum the floor a second time.

For a more thorough step-by-step walkthrough on how to vacuum the pool, check out my vacuuming guide.

Step 4: Backwash or Clean the Filter

With all of the gross dead algae now in your filter, you’re going to have to clean your filtration system. Depending on the type of filter you have, you may need to either backwash it or manually clean the filter elements to remove the collected debris. Here’s how to do it:

Backwash Method

If you have a sand or DE filter, you can backwash your filter to get rid of the dead algae. To do so, turn off the pump, switch the valve to backwash, attach the backwash hose, and direct the other end to an appropriate drainage area. Then, turn on the pump and backwash the filter for two or three minutes or until the water runs clear. Finally, run the filter on the rinse setting for around 10 seconds before returning the valve to the filter setting.

If you have a DE filter, you will also need to add some more DE powder at this point.

Manual Cleaning Method

If you have a cartridge filter, you will need to manually clean the filter elements. To do so, turn off the filter and bleed the air. Then remove the cartridge filter and wash it by spraying it with a hose at a 45-degree angle. The next step is to soak the filter in a bucket of a commercial filter cleaner and water, according to the manufacturer’s instructions. Soak it for up to 10 hours. Finally, remove the filter from the bucket and thoroughly rinse it before putting it back in its housing unit and restarting the filtration system.

If your cartridge filter is still dirty after soaking it in a solution for 10 hours, you may need to do a second soak in a bucket with a mixture of one part muriatic acid to twenty parts water.

Step 5: Test and Balance Water Chemistry

Now that you have managed to get rid of all the dead algae in your pool, it’s time to get your pool ready for use again. Grab your handy pool water testing kit and test the pool water. Balance any chemicals needed to avoid any unwelcoming algae growth in the future.

What Does Dead Algae Look Like?

Any decent pool owner will know how to identify live algae, but what about dead algae? Dead algae generally looks like a brownish dust cloud. It can be found suspended in the water, on surfaces, or at the bottom of the pool. More often than not, dead algae will also give the water a cloudy or murky appearance, obscuring the pool’s clarity. If you notice any of these visual cues, it’s a sign that you need to take action to remove the dead algae and restore your pool’s pristine condition.

How to Tell If It Is Dead or Live Algae?

If you’re unsure whether you’re dealing with live or dead algae, give it a quick brush. If it smears, it’s live algae. And, on the other hand, if it brushes off easily, it’s dead!

Causes of Dead Algae Accumulation

Dead algae accumulation in your pool can be attributed to a combination of factors that create an ideal environment for algae growth and persistence, such as:

  • Inadequate filtration. Insufficient filtration can result from a clogged or undersized filter system. Or maybe, you’re simply not running your filter often enough. Ideally, you should run your filter for 8 to 12 hours a day. Inadequate filtration means that after shocking your pool, dead algae can settle and accumulate.
  • Insufficient cleaning and maintenance. Neglecting routine cleaning and maintenance tasks, such as skimming, brushing, and vacuuming, means the dead algae in your pool may settle on your pool floor and surfaces.
  • Improper chemical balance. An imbalance in pool chemistry, particularly low chlorine levels or incorrect pH, weakens the pool’s defense against algae. This may lead to algae, which will eventually lead to dead algae accumulation and unsightly water conditions.

Addressing these causes through proper filtration, balanced chemistry, and regular maintenance can significantly reduce the risk of dead algae accumulation and maintain a clear, appealing pool.

And, of course, most importantly, you need to know how to prevent algae from blooming in your pool in the first place. For more on this, check out my complete guide on how to get rid of algae.

How to Filter Dead Algae

To effectively get rid of the dead algae in your pool, you need to filter the pool. After you follow all of the above steps, including skimming, brushing, vacuuming, backwashing, and rebalancing the pool chemicals, you must also ensure you thoroughly filter the water. Keep your pool’s pump and filtration system running for 24 to 48 hours to thoroughly circulate and clean the water of any remaining debris or dead algae. Make sure to check and backwash/clean your filter regularly as the debris and dead algae build up in your filtration system.

What to Do If Dead Algae Clogs Your Filter

Encountering a clogged filter due to dead algae demands prompt attention! To deal with this, start by turning off the pool pump to prevent further clogging. Then, clean or backwash the filter, removing the trapped dead algae and debris. Depending on the severity of the clog, you might need to perform multiple cleaning cycles. To prevent clogs, make sure to regularly monitor and maintain your filter. 

Get My Free Pool Care Checklist

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Frequently Asked Questions

Can flocculant remove dead algae?

When it comes to dead algae, flocculants can be super helpful. This chemical helps clump up the dead algae particles, making it easier for you to clean up. However, don’t use flocculant as your only method of getting rid of dead algae; proper filtration and vacuuming are essential to fully address this problem!

Will shocking remove dead algae?

No, shocking a pool will not directly remove dead algae. While shocking can help kill live algae and bacteria, it won’t physically remove dead algae from the water. Dead algae particles may settle to the bottom of the pool or may need to be physically removed through filtration, vacuuming, or other cleaning methods.

Can you use an automatic cleaner to remove dead algae?

Yes, you can definitely use an automatic pool cleaner to remove dead algae. These cleaners move around the pool, scrubbing surfaces and collecting debris, including dead algae. While they may not remove all dead algae on their own, they can be a helpful tool.

Here are my top picks for automatic cleaners.

Enjoy Your Clean Pool!

As you can see, getting rid of dead algae in your pool is not as difficult as it seems. All you need is a little patience and a bit of elbow grease, and with the help of your vacuum and filtration system, voila! You’ll be enjoying your sparkly clean pool again in no time! Remember, timely action and consistent maintenance are key to preventing future algae woes – whether dead or alive.

Got more questions about getting rid of dead algae in your pool? Feel free to ask; I’m here to help!

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