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Pool Clarifier vs. Pool Flocculant: What’s the Difference?

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Say it’s the middle of summer, and you’ve planned a big pool party. But the pool is cloudy! No one’s going to swim in that! Should you use pool clarifier or flocculant? Knowing which one to use and when is a matter of understanding how each one works.

What’s the Difference Between Pool Clarifier and Pool Flocculant?

Pool clarifier coagulates (combines) tiny particles into small clumps so they can be removed by the pool filter. It’s effective, but it may be days before it clears the pool water. Pool Flocculant (a.k.a Pool Floc) combines debris into large clumps that sinks to the bottom of the pool. Then, it has to be removed manually with a pool vacuum. Floc is faster but it requires more work.

What is Pool Clarifier?

Sometimes, the little nasty things that create a cloudy pool are just too small for your filter to capture. They pass through the filter’s medium and head right back into the water.

Pool clarifier contains polymers that act as coagulants on these tiny particles. When you add a clarifier to cloudy water, all those tiny particles clump together into bigger particles your filter can capture and keep from reentering the pool.

Note: It’s usually perfectly safe to swim in a cloudy pool. Just keep in mind that visibility underwater will be limited, and opening your eyes underwater may cause irritation. For safety and comfort, we highly recommend skipping the swim until you’ve cleared the water.

Pool Clarifier Benefits

Knowing the benefits and downsides will help you decide whether this is the right chemical for the occasion.

Pool Clarifier Drawbacks

It seems like a magical pool chemical, but just like anything, it does have its downside.

Clorox Super Pool Water Clarifier
$9.88

Your filter can clear a cloudy pool. But your filter needs help picking up particles that are too small. A clarifier binds these particles together, so your filter can remove them easier.

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How to Use Pool Clarifier

It’s easy to use, but it’s important to follow the correct steps to avoid making the problem worse.

Important: If, in addition to cloudiness, you also have algae in your pool, address that problem first before using trying to clear the water. No amount of clarifier is going to get rid of algae.

  1. Balance the pH in your pool. It should be between 7.4 and 7.6.
  2. Read the manufacturer’s instructions. Pool clarifier use isn’t very complicated, but you may find minor differences between the brands, so make sure you’re following those directions.
  3. Determine your pool’s volume, if you don’t know it off hand. You can do this easily with a pool calculator.
  4. Add the correct amount of clarifier according to your pool’s volume.
  5. Turn on the pool filter, and run it 24/7 (or as much as you can) until your pool is clear.
  6. Clean the pool filter.
  7. Check your pool’s pH level again. Some clarifiers may increase it. Balance it (and all other levels) again, if necessary.
  8. Get back to enjoying your pool!

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What is Pool Flocculant?

Also known as pool floc, this chemical is like a super-powered version of clarifier. It also causes the particles in your pool to coagulate and clump together. The difference is, flocculant creates larger clumps that sink to the bottom of the pool, and cannot be removed by your filter.

Frustrated by adding chemicals and trying to keep your pool clear all the time?

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Pool Flocculant Benefits

You may find the pros make it a more desirable option than clarifier.

Pool Flocculant Drawbacks

Before you opt for floc over clarifier, make sure you know what you’re getting yourself into.

Pool Flocculant Water Clarifier
$49.94

Pool floc binds particles (and dead algae) that are making your water cloudy together and sinks to the bottom of your pool so you can easily vacuum out the cloudy mess.

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How to Use Pool Flocculant

  1. Turn your sand or DE filter’s multiport valve to Recirculate.
  2. Balance the pH in your pool. It should be between 7.4 and 7.6.
  3. Read the manufacturer’s instructions on the package. Pool flocculant isn’t difficult to use, but you may find a few differences between brands, so make sure you’re following the directions for the one you choose.
  4. Figure out your pool’s volume, if you don’t already know it. You can use a pool calculator to help you.
  5. Add the correct amount of flocculant for your pool’s volume.
  6. Run the pool pump for two hours to circulate the floc throughout the pool.
  7. Turn off the pump, and allow the pool to sit for eight hours. This is easiest to do overnight. If you have an automatic timer set, remember to turn it off.
  8. Turn your pool filter to Waste.
  9. Connect your manual vacuum.
  10. Vacuum the particle clumps from the bottom of your pool.
    • The movement of the vacuum may stir the particles up, clouding your pool again. If this happens, take a break, allow the particles to settle, then begin vacuuming again, and try to move slowly.
    • You may need to vacuum two or three times to remove all the clumps.
  11. Check the pool’s water level. If it’s gone down (it likely will), use a garden hose to add fresh water and bring the level back up where it needs to be.
    • You may also keep the hose in the pool while you’re vacuuming, though this may also cause the particles to be stirred up while you’re removing them.
  12. Balance the water.
  13. Dive in!

Important: Triple-check to ensure your filter is set to Recirculate before you begin this process. Do not allow pool flocculant to get into your filter. Imagine this heavy-duty coagulating agent in your filter. It’ll block everything up in no time, rendering your filter useless until you get the floc outta there, which will likely require replacing the medium altogether. That’s a lot more work than just the vacuuming you need to do, so save yourself the trouble and make sure you’re vacuuming to waste.

So Which One’s Better?

The big difference between these two pool clearing methods is time. If you want the water clear for that pool party before everyone shows up, go for pool floc. It’s more work, but it’s faster.

If you just opened your pool or it’s just a little cloudy, and you have time, opt for the pool clarifier.

You’ve Got Sunshine in a Cloudy Pool!

So it’s not that pool clarifier is better than pool flocculant. They just work differently. In fact, this is a benefit to both of them because now you have a choice of how to clear your pool depending on what’s going on in your life.

And that’s the way it should be. You should have a choice and not allow your life to be dictated by the condition of your pool. It’s there for you to enjoy, as long as you take care of it.

Happy Swimming!

Matt Giovanisci is the founder of Swim University® and has been in the pool and spa industry since 1995. Since then, his mission is to make pool and hot tub care easy for everyone. And each year, he continues to help more people with water chemistry, cleaning, and troubleshooting.

Frustrated by adding chemicals and trying to keep your pool clear all the time?

We cut out all the confusion of pool maintenance in this easy-to-read illustrated ebook and video course. It'll help you save $100 right away on pool care!

Click Here to Learn More
The Pool Care Handbook

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