Learn How to Remove Dead Algae from Pool Bottom In 3 Steps

You can do so by keeping an eye on the water chemistry and using chlorine shock treatment. Properly cleaning, scrubbing, and vacuuming the pool along with using the pool pump properly will help you get rid of the dreadful algae for good. 

What better way of finding relief from the scorching summer heat than diving into your swimming pool? But you wouldn’t want to swim in an algae infested pool, would you? Algae is a stubborn, uninvited guest living in your pool that is hard to get rid of. 

Don’t worry – we have got your back. We will tell you all you need to know about how to remove dead algae from the pool bottom! You will not only be able to remove the dead algae completely, but you will also be able to keep it away for good.

how to remove dead algae from pool bottom

What Causes Algae Bloom in Your Pool?

At times, despite cleaning our pool regularly, we can’t seem to keep the horrendous algae away. There are a few things that can cause algae bloom in the pool such as:

  • Lack of Circulation
  • Improper Filtration
  • Poor Sanitation

Despite our best efforts to keep the pool clean, we still end up with a huge algae problem at our hands. Algae particles are very small and fine in nature, and even though your filter is working properly, the particles settle down and cover the pool bottom.

Why is Algae Bad for Your Swimming Pool

Even though algae doesn’t cause you any harm when you swim, there are several reasons why you should keep your pool algae free.

  • Dead algae clouds and discolors the water.
  • It confuses the diver regarding the pool’s depth.
  • Algae blocks the water sanitation lines and clogs the holes in the pool as well.
  • It reduces the effectiveness of the pool filter, and you need to replace the filter more often – which can be a bit heavy on the pocket!
  • The pool area becomes slick, slippery, and greasy. This increases the chances of unforeseen accidents.
  • Above all else, no one wants to swim in a pool that has algae all over it!

How to Get Rid of Dead Algae from Pool Bottom

No one likes a dirty, stinky pool. Removing algae from your pool isn’t rocket science. With the proper instructions and equipment, you can easily become an algae-killing expert. Here’s how you can easily remove dead algae from the pool bottom to have a clean, sparkling pool in no time!

Remove the Floating Debris

Supplies Required

  • Pool Cleaning Net
  • Skimmer Basket


  • Most of the dead algae are in small, fine pieces that can be easily removed using the pool net. Use the pool net to remove all the floating debris, including leaves and floating algae from hard to reach areas such as pool corners.
  • You can also use a skimmer basket to skim the algae floating on the surface of your pool.
removing debris and leaves from pool

Scrub the Pool

Supplies Required

  • Steel Bristle Brush
  • Soft Bristle Brush


  • Empty out the pool completely. 
  • Use the brush to loosen the algae clinging to your pool walls. The kind of brush you use will depend on the surface of your pool. If your pool is made of plaster or concrete, you will need a stiff pool brush. For vinyl or fiberglass pools, use a soft bristle brush. 
  • Scrub the pool completely – from the bottom to the walls to ladder steps to each and every nook and cranny. 
  • Wash it away with clean water.

Clean the Filters


  • Take out your pool filter.
  • Thoroughly wash it in lukewarm water.
  • If your filter has some specific cleaning instructions, make sure you follow them.

Alternative Option – Vacuum the Pool

Once you have brushed and scrubbed the pool, you can vacuum it. It will help you get rid of all the dead algae fragments left behind. You can use robotic vacuums or manually vacuum your pools to get the job done. 

There are two ways of cleaning your pool using a vacuum. 

For Pools with Multiport System

If you have a multiport system, you can use a pressure-side or suction side vacuum. Set the system to the ‘waste’ setting. For pressure side vacuum, connect it to the dedicated suction line. In case of a suction side vacuum, connect it to the skimmer.

The algae will go through the pump and pipes and will bypass the filter on its way out of the pool system. This will keep the filter from getting clogged up. Moreover, it ensures that the algae are not reintroduced into the pool.

For Pools without Multiport System

If you don’t have a multiport system, you can simply send it through the filter in your pool. However, once you vacuum the algae through the filter, the filter will become essentially useless. Vacuum the pool on a weekly basis.  

How to Prevent Algae in Your Pool

Now that you know how to remove dead algae, the million-dollar question is: How to keep the algae from blooming again? Algae are pretty hardy – if they want to stay alive, they will figure out a way to do so even in the toughest circumstances. Therefore, you need to take some precautionary measures to get rid of the algae in your pool. Let’s see how!

Balance the Water Chemistry

The first thing you need to know is the water chemistry of your pool. 

Supplies Needed

  • Water pH Test Kit
  • Sodium Carbonate


  • Check the pH and chlorine levels in your pool.
  • Add sodium carbonate and bring the pH level up to 7.8.
  • To maintain the chlorine levels, add sodium bisulfate.
  • The chlorine level, at the very least, should be above one ppm.
swimming pool ph check

Keep the Pump Running

Most of us run the pool pump for about 6 to 8 hours per day. However, when you are treating your pool for algae, you need to keep the pump running for 24 hours. The pump not only helps you filter the water but also circulates the chemicals such as chlorine throughout the pool, keeping algae at bay. 

Use Calcium Hypochlorite

Check the color of the algae. If it is green, it means the algae is not dead. Even if you clean the pool, the algae will keep coming back unless you shock the pool.

Supplies Required

  • Calcium Hypochlorite


  • Add ½ cup calcium hypochlorite per 1 liter of water in your pool. It will kill all the algae that are present.
  • Let it sit for 15 minutes.
  • Clean out the pool thoroughly to prevent algal regrowth.

Use Algaecide

Algaecide prevents algae growth and helps you maintain sparkling water in the pool. Rather than being a reactive treatment, it is a preventive one. 

Supplies Required

  • Algaecide


  • Buy some algaecide from your local home improvement store.
  • Add 1 cup of algaecide per 2 liters of water. However, you can check the package for more instructions and follow them according to the size of your pool.
  • Drain the pool and scrub it thoroughly.

Use Chlorine Bleach

Chlorine shock treatment is very helpful when it comes to removing algae, bacteria, and other germs from your pool. Prevention is always better than the cure – use a chlorine shock product to keep your pool water crystal clear. 

Supplies Required

  • Chlorine Bleach
  • Chlorine Tablets
  • Gloves


  • Wear gloves before handling the chlorine bleach.
  • Add ¼ cup of chlorine per 5 liters of water. 
  • Let the chlorine sit in the water for 10 minutes.
  • Drain the pool.
  • You can get chlorine bleach tablets as well such as Clorox. 
  • The water will look a bit cloudy after you add chlorine tablets. However, it will clear up in a day or two. Don’t let anyone into the pool before the water clears up after chlorine shock treatment.

Use Flocculant

Flocculants are fast and effective when it comes to removing algae. They coagulate algae into small particles that can be then manually removed. 

Supplies Required

  • Flocculant


  • Add pool flocculant to the water. Follow the instructions given on the box to add the exact amount of flocculant. 
  • After 5 to 10 minutes, the algae will coagulate, clump up, and sink to the bottom. You can use the vacuum to suck the clumps up.
  • You can use a pool clarifier instead of a flocculant as well. In the case of a clarifier, the algae clumps will not sink to the bottom, but will rather stay on the surface of the water. You can skim them off with a pool net.

Frequently Asked Questions

For dead algae removal, are sand filters better than cartridge filters?

Sand filters work best when it comes to removing dead algae as compared to cartridge filters that get dirty very easily.

How can I identify dead algae?

Usually, algae are green in color. However, it can take on different colors depending on various environmental factors such as oxygen, sunlight, etc. When it dies, algae turns black or brown.

Scroll to Top