What is Pool Flocculant?

Pool flocculant, also known as pool floc, is a helpful chemical agent designed to clear up cloudy water in swimming pools. Flocculant can come in powder or liquid form, and it works by clumping together harmful water impurities — bacteria, viruses, algae spores, and other microscopic debris — which then sink to the bottom of the pool to be easily vacuumed away.

How Pool Flocculant Works

Though a filtration system and regular vacuuming are chief defenses against a dirty pool, an array of tiny debris can accumulate, especially if the pool is outdoors, making murky water that won’t look good or feel good to swim in. Pool flocculant is a very effective and fairly quick solution for this phenomenon that every pool owner will encounter from time to time.

Flocculants are a specialized formulation of chemical compounds with positive charges that attract fine debris with negative charges so that they form clumps that are large enough to sink to the bottom of the pool. Think of it as glue for particles that are too tiny for the pool’s filtration system to extract from the water.

This process clarifies cloudy water and also makes it easy to spot the gunk that will need to be manually sucked up by a pool vacuum. Follow manufacturer directions to apply the flocculant to the water, let it work overnight (or sit for at least eight hours), and then vacuum the next day.

Types of Pool Flocculants

Pool flocculants can come in liquid, tablet, and powder form. The right choice and how much you need depends on the volume of water and type of pool. Doheny's Extra-Strength Pool Flocculant, for example, advises just 8 ounces for 10,000 gallons of water, while Maintain Pool Pro’s Granular Floc recommends one pound per 5,000 gallons.

Floc is readily available to order on Amazon or pick up at Home Depot, Lowes, and Walmart. Or shop local and support small business by visiting a nearby pool supply store. Select a pool floc specifically designed for your pool treatment method, which may be chlorine, bromine or salt, and read the label to make sure it’s compatible with your filtration system.

If you have any questions about pool flocculant, feel free to contact White’s Pools for professional consultation. We’re also available to do the job for you.

How to Use Pool Flocculant

Before adding pool flocculant to cloudy water, there are a few essential steps to take in order to make the chemical treatment effective and avoid potential damage to your pool system.

Check your water level and balance pH

This entire process will likely cost your pool some water, so make sure it’s as full as possible to avoid water level dropping below the filters. Then, balance pH levels between 7.2 and 7.6 to ensure proper sanitation of the water throughout the cleansing.

Dilute and Add Flocculant to Pool

A 5-gallon bucket is a good tool to have handy to both dilute and distribute the pool floc. Read the manufacturer’s directions on the packaging carefully to determine the correct amount of water to add to the flocculant based on the overall volume of water in your pool. Once diluted, add the floc to the pool water. Again, follow manufacturer’s directions, but a common tactic is to pour around the edges of the pool.

Turn on Pump to Circulate Flocculant

The pool pump will distribute the chemical compound evenly throughout the water. Be sure to set the pump to “recirculate,” not “filter,” and leave on for about two hours.

Allow Pool Flocculant to Settle for at Least 8 Hours

Turn the pump off and let the pool floc sit in the water, coagulate the dirt, and then settle at the bottom of the pool.

Turn on Pump, Set Filter Valve to “Waste” and Vacuum

After letting the pool floc work in stillness for 8 hours, you’ll notice a layer of sediment at the bottom of the pool. Now it’s time to vacuum manually (carefully and thoroughly) while the pump simultaneously filters the water.

Add More Water and Balance pH Levels

The vacuuming process may have drained your pool of a lot of water, so again, fill back up to make sure it’s above the filter, and check for balanced pH levels.

Backwash Pool Filters

In order to avoid leftover pool floc chemicals or coagulated sediment from lingering, wrap up by backwashing your filters.

How to Get Flocculant Out of Pool Without a Vacuum

No vacuum? No problem. There are other techniques and tools to get the coagulated gunk out of your pool without the aid of an electronic vacuum, they just require a little more elbow grease.

Grab a pool rake and gently drag the mesh net against the bottom of the pool to scoop up the debris. No pool rake either? Try a pool skimmer net instead. Whether you’re vacuuming, raking, or skimming, make sure you turn the pump back on, setting the valve to “waste,” to capture other residue that may still be suspended in the water.

Flocking a Pool with Different Filter Types

Flocculant is only advised for pools with a Sand filter or DE filter. The former is most suitable for using flocculant because sand media can effectively trap the large clumps created by the flocculant. A DE (diatomaceous earth) filter also has fine filtration capabilities so it can handle flocculants effectively.

DO NOT, however, use a pool floc with a cartridge filter! The clumped particles can severely clog the filter, which will reduce the water flow and may require replacing the cartridge entirely. Though there are people online who claim to have used pool flocculant with a cartridge filter successfully, do so at your own risk!

Pool Maintenance After Flocculation

Proper pool flocculation requires patience and maintenance. Follow manufacturer directions for the product you purchase, but expect to turn the pump off and wait at least 8 hours for the pool floc to coagulate the dirt particles and then settle on the floor before vacuuming it all up to waste. After vacuuming, check on the filter and consider backwashing to remove any sediment and accumulated floc particles. You also may need to add more water to the pool since it may be lost during the vacuuming process. Additionally, make sure the water remains chemically balanced. Monitor pH and chlorine levels.

Common Pool Flocculation Issues

If water is still cloudy after pool floc treatment, there are a number of issues to consider that could be at the root of the problem:

• Improper Vacuuming: Firstly, make sure your filter mode is set to “waste” before vacuuming, otherwise the filter will send the dirt sucked up right back into water circulation. Additionally, the clumps of particles attracted by the floc could break apart if the vacuum is moved too fast along the bottom of the pool, sending debris back into the water. Move slow and carefully for best results.
• Floc in the Filter: Another reason to beware of vacuuming the residue into the filter is because the particulate matter clumped by the floc will break down again over time and be distributed back into the water, slowly building back up the cloudy conditions the pool floc was supposed to cure.
• Over-flocculation: It’s important to follow manufacturer directions and add the right amount of pool floc for the right amount of water. If too much pool floc is added, small floc particles can stay suspended in the water, making the pool appear even cloudier and potentially clogging the filter.
• Under-flocculation: Conversely, not adding enough floc to the pool will also prevent the treatment from being effective.
• Weak circulation: If water isn’t being circulated around the pool in proper fashion, the floc may never actually settle at the bottom of the pool.

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

Is pool clarifier the same as flocculant? Both pool flocculants and pool clarifiers are used to clear up cloudy water in swimming pools, but there is one big difference between the two: speed!

Clarifiers are less powerful chemical agents and need several days to clear up cloudy water, while a flocculant can do the trick in as little as eight hours.

Flocculants, though more effective, also require more labor. Once the fine particles plaguing the water are clumped together into larger chunks, they sink to the bottom of the pool and need to be manually vacuumed up. The particles that clarifiers coagulate, meanwhile, can be automatically removed by your pool’s filtration system over a longer period of time.

Consider using a pool clarifier if the water isn’t excessively dirty and you’re not in a pinch for time. But if you’re expecting guests in a few days and need to purify your pool water fast, reach for the flocculant.

Can You Swim with Flocculant in the Pool?

Simple answer: no.

The clumps of grime that the flocculant is coagulating can irritate skin and eyes. Stay out of the water while the chemical agent does its work, and only open the pool back up for swimming once the clumps that sink to the bottom are vacuumed up. Experts recommend no swimming for 24-48 hours after pool floc treatment.

Additionally, it’s not recommended to swim in cloudy water that needs pool flocculant treatment, either. Water that appears cloudy is likely full of harmful contaminants that can also cause eye and skin irritation. Plus, decreased visibility only increases the odds of drowning. A clean pool is a safe pool!

Can You Swim with a Pool Clarifier in the Water?

Yes, you can. And some may see this as another advantage of using pool clarifier over pool flocculant. Pool clarifiers are designed to be non-toxic and non-irritating to swimmers, so you can safely jump right in after adding if you want. It is, however, recommended to wait at least 20 minutes before doing so in order to allow the substance to distribute evenly throughout the water.

Homemade Pool Flocculant

Though a quick Google search for “homemade pool flocculant” will suggest grabbing Aluminum Sulfate from your local garden center and distributing the dissolved alum evenly across the pool surface, and then waiting a few hours for the chemical compound to attract particles into clumps, the fact remains that this or other homemade remedies for cloudy water may not be as safe or effective as commercial pool flocculant.

Pool flocculants are composed of specialized chemical compounds not easily found at home or in stores, so it is recommended that pool owners trust the experts instead of attempting to formulate homemade pool flocculant.

Don’t Want to Do This Yourself? Hire an Expert!

White’s Pools doesn’t just design and install pools, we’re trusted experts to help maintain them, too. If flocking a pool sounds like too much work for you, whether you don’t have the confidence or time to get the job done, just call White’s.

We’ll handle the entire pool flocculant process from start to finish so you can focus on planning more important things — like the guest list and menu for your next pool party — and let us worry about crucial maintenance, including pH level and chemical balancing, cleaning and debris removal, and equipment inspection.

We can also consult to develop a plan for regularly scheduled maintenance visits to ensure that potential issues are spotted and addressed before they become significant problems. Contact us today!