This may be a new word for you in the context of swimming pool maintenance, but it is one you need to know: Flocculant (pronounced floc·cu·lant).

Sometimes also referred to as “pool floc”, it’s another useful chemical that helps clean up the cloudy water in a swimming pool. In some cases, it’s actually the best chemical to pull out of your pool supplies shed when your filtration system isn’t keeping up with the cloudiness in the water.

This article breaks down everything you need to know about pool flocculants:


What Is Pool Flocculant Exactly?

Pool floc can help keep your pool as clean as possible for longer periods and not a ton of work. This chemical causes the tiny particles in your pool, like viruses, bacteria,  algae spores, and other microscopic debris, to clump together and then fall to the bottom of the pool. Pool flocculant takes 8 to 16 hours to do this work. 

In the meantime, the pool has to stay closed to swimmers. It is dangerous to allow people into a pool during this time. But the use of a floc can clear up cloudy pool water in 1 or 2 days.

Once the chemical has had enough time to gobble up all these particles, you will need to vacuum them up off the bottom.

Your pool filter must have a “waste” setting. The clumped particles can’t be removed by the filter, so the filter is bypassed and the flocculant is vacuumed out of your pool manually.


What’s the Difference Between Flocculants and Clarifiers?

Good question! Both flocs and clarifiers have the same goal: to clear cloudy pool water. And don’t forget you still must maintain proper pH levels at the same time. Now, if you are a new pool owner, you may be totally confused. So let’s differentiate between flocculants and clarifiers.

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When using a flocculant in your pool, you will get results faster than with clarifiers. The clumps are larger, so they can’t go through the filter.

The floc works faster and is more effective than a clarifier. One reason is the clumps stay together; they don’t leave bits of “stuff” in the pool as you vacuum them up. Those particles can leave cloudy spots in the pool.  Also, you can be back in the pool within a day or so, depending on how long it takes you to do the vacuuming.



Pool clarifiers cause those small particles that find their way into a swimming pool to clump together, too. The difference is that the clumps are smaller than what occurs after using flocs, so the pool filter can remove them without damaging the filter.

This process can take two to three days for the clarifier to do its work. This means that your pool is closed to any swimmers during that time.

If your pool water is marginally cloudy, experts recommend using a clarifier first. But, if the clarifier doesn’t bring the results you want, you may have to switch to a flocculant. All of this simply adds time to clear the water in your pool.

Based on this information, why wouldn’t everyone use pool floc instead of a clarifier?


Downsides of Pool Flocculant

There are a few negatives to using pool flocculants instead of clarifiers:

– If you have a cartridge filter, you can’t use a pool flocculant. To do so would require a custom plumbing setup that has the ability to bypass the filter when you vacuum. The filter would need to be a sand filter or a diatomaceous earth (DE) filter, and the results may not be as acceptable. 

– Because of the need to manually vacuum the clumps off the bottom of the pool, a floc simply requires more work on your part. Unfortunately, automatic pool vacuums can’t handle this task for you.

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– You’ll lose some pool water using a pool flocculant. As you bypass the filter to vacuum the clumps out, water is also leaving the pool. The water level will drop and have to be replaced before re-opening the pool. Once you add water, you’ll need to test the water chemistry and rebalance it as necessary, specifically the alkalinity and pH. Once those levels are balanced, you’ll need to add chlorine.

The good thing is, when it comes to using pool floc properly, Pool School Videos can help!


Professional, Easy-to-Understand Help is Available!


Taking care of a swimming pool can be a daunting task and one of the most frustrating problems is a cloudy pool. There are several ways and products to clear the water; the trick is which one to use. Both pool flocculants and clarifiers are designed to do the job and both have advantages. But which is best for your pool?

Choosing a pool flocculant or clarifier doesn’t have to be a difficult decision. “The Pool Doctor” Mike Steele has created Pool School Videos for issues just like this. You’ll get in-depth information on how to handle both common and not-so-common pool maintenance problems. 

With our 20 online, self-paced pool maintenance videos, you will have expert information that addresses everything in simple, easy-to-understand language. You’ll be able to actually enjoy your pool instead of spending all your time and money trying to maintain it. Once you buy Pool School Videos, you can watch them whenever you want and as many times as you need to.

With your purchase, you’ll also become a member of the Pool School Videos private Facebook group. Here you can ask specific questions that you have and get a personal response with customized guidance within 24 hours!

To get a sneak peek and meet the Pool Doctor, Mike Steele, preview our top 5 videos. Then get started mastering your pool maintenance efforts with Pool School Videos today. Don’t wait! Get started now!