Select Page

If you’ve tried several methods to get your pool clear and it still hasn’t worked, you might need pool flocculants. Flocculants can clean a pool fast which is ideal if you have a party or even planned for your pool.

If you’re unsure how to add this chemical to your pool, we created this guide to help. We’ll go over the vacuuming process, how to add the flocculant, and how to treat your pool after cleaning it.

Keep reading to learn more about how to use this clarifying chemical!

How Does Pool Flocculant Clear Water?

Pool flocculant is a chemical that causes debris in the water to clump together and sink to the bottom of the pool. Flocculant is usually added to pool water when it’s very cloudy and other pool clarifiers have failed.

Aluminum sulfate is the main ingredient in flocculant. Aluminum sulfate is a binding agent, which means it binds to almost any substance, like dirt, clay, algae, and other plant material.

Adding floc, a short name for pool flocculant is one of the fastest and most effective tools for clearing cloudy pool water. Within 1-2 days this clarifier can draw dirt, natural compounds, and bacteria out of the pool’s water.

This debris is easier to vacuum out of the water than it would be if you tried to vacuum small waste particles. While it does work as a pool clarifier, it’s not the same thing as standard clarifiers.

It’s more effective and potent, but also more labor intensive. It is the best choice though if you plan on having a pool party and need your cloudy pool water clarified fast!

How is Pool Flocculant Different Than Pool Clarifier? 

The main difference between pool flocculants and pool clarifiers is how they work. While both compounds bind to elements in the water, how these chemicals work differs slightly from one another.

Pool flocculants bind heavy elements in the water and form large clumps. The clumps then sink to the bottom of the pool and must be vacuumed up. These clumps are too large to fit through the pool filter.

A pool clarifier forms small particles that are carried into the pool’s filtration system. The particles are then caught in the filer’s medium, like sand or diatomaceous earth (DE filters). This allows fresh, clean water to be pushed back into the pool.

The size of these debris collections and how you will have to clean them up are the primary differences between clarifier and flocculant. Pool clarifiers are known to do a more thorough clean-up, but take several days to completely clear a cloudy pool.

Pool flocculants are quicker and typically only take a day or two to clear the pool water. However, you’ll have to put more effort into the cleanup and will lose more water than when using a pool clarifier. Since the only way to clear the clumps from the water is to vacuum them into the filter, you’ll have to backwash them out of the filter when you finish.

How to Use Pool Flocculant in a Swimming Pool? 

To add pool flocculant to your swimming pool you’ll need to do the following:

  1. Test pool water pH levels
  2. You may want to add a little extra pH because you will lose water
  3. Set your pool filter to recirculate (do not set it to filter setting)
  4. Add pool flocculant to the pool water (follow the manufacturer’s instructions regarding dosage and preparation)
  5. Run the pool pump for 8 hours to circulate the pool flocculants
  6. Use your pool vacuum to pick up the water from the pool floor
  7. Set your pool filter to waste so the particles are removed from the water as you vacuum
  8. You may need to add water to the pool as you go to prevent your pool’s pump from sucking air instead of water
  9. Once you finish, test your water’s chemical levels and replenish the water you lost
  10. Add pH increaser or decreased as needed based on your chemical test
  11. Set your filter system to normal and leave it running to circulate the chemicals

Does Pool Flocculant Take a While to Work? 

Pool flocculant is much faster acting than pool clarifier. It’s one of the best choices if you need clear water for an upcoming party or outdoor activity.

Pool flocculant typically takes about 1-2 days to clear cloudy water. Although the chemical only takes 8 hours to clump debris in the water, it can take a while to clean it and rebalance it after you finish.

The time it takes to clean up the pool flocculant and clumps of debris is the reason you should give yourself 1-2 days. While the chemical is fairly fast acting, the clean-up can be a little time-consuming.

Is Pool Floc Worth the Time and Effort? 

Pool flocculant is worth the effort and time because it will leave your pool looking good and clear. This is especially true if you have cloudy pool water for days and nothing else seems to be working to clear it up.

While a pool clarifier works well to get your pool clean, it’s not as fast at clearing cloudy water particles. Before using pool flocculant you should use other methods to clear cloudy water, like shock treatments or balancing your pH levels.

Pool flocculant is best used when you haven’t had success elsewhere. This is mainly because pool flocculant wastes significant water in the clean-up process. You won’t want to waste your pool water and chemicals in the backwashing process unless it’s necessary.

Does Pool Floc Work with a Sand Filter Pump? 

Pool flocculant, or pool floc, works with sand filters and DE filters. The important thing to have is a pool vacuum and a filter system has a waste setting. You should never use a pool flocculant in a filter system that won’t allow you to flush the clumps directly out of your pool pump.

Finally, avoid using a pool flocculant with cartridge filters. This filter isn’t a good option because the particles will ruin the filter element. While you can use pool flocculant with these filters, you’ll have to replace your pool filter and media.

Alternatively, you can remove cartridge filters when using pool flocculant to clear cloudy pool water. You’ll have to install a few bypass valves, however. But if you’re knowledgeable about plumbing, this shouldn’t be too difficult and will allow you to add pool floc without damaging your filter.

How Can You Prevent Cloudy Pool Water? 

Two of the best ways to prevent cloudy water are by regularly cleaning and balancing your pool water. Pool water becomes cloudy when the pool chemicals aren’t balanced and becomes a breeding ground for bacteria and algae.

Therefore, the first thing you’ll want to start doing is testing your pool water every day or two. This will ensure your water’s pH level remains at an even 7.4-7.6. When the water is too acidic or alkaline it can interfere with how your chlorine cleans the water.

An imbalanced water chemistry can cause bodily fluids to accumulate in your swimming pool. If your swimming pool is used regularly, these bodily fluids can throw off your pool’s chemical balance. This can cause your pool’s water to become contaminated and cloudy.

Use pool nets, brushes, and vacuums to regularly remove leaves, algae, and other organic material from the water. Organic matter introduces new bacteria and algae spores to your pool that can make your water cloudy and slimy.


Always use a pool water clarifier before adding flocculant to your pool. Clarifiers are effective and less wasteful than a pool flocculant and thus should be used when time permits.

Only use flocculant if your pool filters are either sand or DE. If you have a cartridge filter, either remove the filter or use a valve to bypass it.

Pool filters must be back washed every time you use flocculant in your pool. Remember that proper pool maintenance will prevent cloudy pool water and prevent the need for pool flocculants!


Can You Swim in a Pool With Flocculant? 

You should not swim in a pool with pool flocculant in it. The pool flocculant needs at least 8 hours to do its job and encourage debris to clump together and sink to the bottom of the pool. if it’s constantly being disturbed by swimmers, it can cause the binding agent to not work properly.

Ideally, you’ll permit the pool flocculant for 24 hours to draw the debris to the bottom of the pool. This will ensure pretty much all the debris is pulled out of the water and resting on the pool’s floor.

If people swim in the pool it can also disrupt your pool’s pH balance. It’s important to keep your pool’s pH level even while the pool flocculant pulls material from the water. Wait until after you vacuum the waste from the bottom of the pool and balance your water before swimming in the pool.

Should You Wait to Add Shock or Chlorine? 

Ideally, you should try pool shock and chlorine before adding pool flocculant to your swimming pool. Only use pool floc after you’ve exhausted other clarifying methods.

You should avoid adding any additional chemicals to your water after adding pool flocculant. After vacuuming the debris from the bottom of the pool and backwashing your filter add chemicals as needed.

Does Floc Remove Algae?

Pool flocculant can remove early algae growth and dead algae from your pool. However, you shouldn’t use floc to kill algae in your water. First, add a shock treatment to your pool to kill live algae before using a pool flocculant to draw the debris to your pool floor.

How Often Should You Clean Your Pool with Flocculant?

There isn’t really a standard amount of times you should add pool flocculant to your pool. Pool floc should only be used in a pinch or when other pool cleaners have failed. Use a clarifier if you’re not pressed for time since clarifiers will save your water.

What Kind of Vacuum Should You Use to Vacuum Pool Waste?

You’ll have to manually vacuum your pool after adding flocculant to your pool. Unfortunately, an automatic pool vacuum will not get the job done correctly. They’re more prone to clog and may disturb the debris on your pool floor as it moves.