Flocking With Sand Filter

Flocking A Pool With A Sand Filter - Is It OK?

Flocculants are exceptionally strong pool cleaning agents that allow even the tiniest particles of dirt and other pollution to be removed from your water. Using a flocculant is not necessarily difficult, but it is a more labour intensive approach than other options.

In this article we will talk about if you can use a flocculant with sand filters, steps to take when using flocculant in pools with a sand filter, and our other recommendations for your situation.

Can You Use Flocculant With Sand Filters?

Flocculants are products that cause debris in your water to stick together in heavy clumps that then sink to the bottom of your pool. Traditionally, these clumps of debris then need to be removed for vacuuming.

No matter what type of filter that you use, whether it be sand, diatomaceous earth, or a traditional cartridge filter, flocculant should never be allowed to pass through your filter. Filters are not able to break down the clumps that are formed by flocculants, leading to clogs in your filter system.

These clogs can lead to permanent damage to your filter and can even cause your pump to burn out if they are not caught quickly enough. To rid your pool of the debris that is accumulated by the flocculant, you will need to vacuum your pool to the waste setting so that everything bypasses your filter.

Using Flocculant With Sand Filters

As long as your sand filter setup comes with a multiport valve with an option to waste, there are additional settings that may allow you to rid your pool of this coagulated debris.

By setting the multiport valve to waste, it is possible to rid your pool of flocculant without vacuuming, but certain other important factors come into play.

It is important to remember that flocculant accumulated waste is very heavy and will settle on the floor of your pool.

This can be convenient if you have a drain on the floor of your pool that is able to be controlled remotely, but most pool owners do not have this feature, and it is still unlikely that this will be able to remove all of the coagulated debris.

In almost all cases, vacuuming the floor of your pool when using a flocculant is an unavoidable step in getting your pool clean. If you are looking for a vacuum-free approach to cleaning up more mild cases of murky pool water, we recommend trying a clarifier instead.

Clarifying products also cause debris particles to stick together in the same nature as flocculants, but unlike flocculants, clarifiers make smaller clumps that are intended to be removed by running your filter.

Clarifiers can be used with most types of filter system, including sand filters.


Flocculants can be used in pools with any type of filter, so long as the flocculated debris is never allowed to pass through your filter system. So yes, you can flock a pool with a sand filter.

Because flocculants require vacuuming in order to finish the cleaning process effectively, you may want to investigate clarifiers if you are looking for a cleaner that allows your filter to do the heavy lifting.

Do you have any questions about using flocculants with sand filters? Drop a question in the comments, we’d love to help you out!

Louis from Pool Advisor


A chemical engineer by trade, Louis is committed to debunking myths in the pool industry by explaining the underlying chemistry and making it accessible to all.