Why Is Dirt Getting Back Into My Pool?

Have you ever finished vacuuming your pool only to realize that all the dirt magically found its way back into your pool? Or, did the dirt shoot through your return jets after going through your filter?

We all know that cleaning and maintaining your pool isn’t always easy. That is why when you realize all of your hard work has been for naught, you tend to get a little frustrated.

There are a few reasons why sand, dirt, and debris might end up in your pool after vacuuming and filtering.

Have You Backwashed Your Filter?

If you have a sand or D.E. filter, you understand that backwashing is a normal part of your pool maintenance routine. If you have a cartridge filter, you are accustomed to cleaning your cartridges yourself. Sometimes, though, after backwashing your filter, you can experience a little dirt back into your pool. Have you ever wondered why?

Sand Filters

If you open a sand filter, you will see a network of tubes called laterals that extend from a central hub. Water passes through the laterals, which also blocks the sand from entering the water. If you find dirt or sand escaping the filter after backwashing, you may have a broken or cracked lateral.

To determine if one of your laterals is compromised, you will have to open the tank and examine the tubes yourself.

In some instances, we have also seen that there could also be an issue within the valve itself. We recommend taking the cover off your valve and inspecting the internal gaskets and O-rings. One of your O-rings may be torn or out of place.

Cartridge Filters

Cartridge filters do not have backwashing capabilities. Filter cartridges must be cleaned by hand or acid-washed. Filter cartridges are made from spun-bound polyester designed to increase surface area for better filtering. If one of your cartridges is ripped, debris can make its way back into the pool.

Whenever you clean your filter, it’s good practice to examine the cartridges for damage and tears.

Diatomaceous Earth (D.E.) Filters

D.E filters, to me, are similar to both sand and cartridge filters. They are similar to sand filters because you will have to backwash them in order to clean them. However, they are like cartridge filters because they use internal grids to filter out debris and dirt.

In some cases, the filter grid may crack or rip, allowing dirt and D.E. powder to pass through the filtering stage and land back in your pool. In this situation, you will have to open your filter and disassemble your grid cluster to examine each grid.

If all of your grids are in perfect shape, remember to check your valve. Open the cover of your valve and make sure the gaskets and O-rings are set properly and are in good condition.

How Old Is Your Sand?

When was the last time you replaced the sand in your filter? As sand begins to deteriorate and break down, the particles become smaller in size. This size reduction allows sand to pass through the filter and back into your pool.

In addition to sand in your pool, you may notice your water is more cloudy than normal. This is also another indication that you need to replace your sand.

Is Your Pump Too Large For Your Filter?

Pool owners often ask if it’s possible to oversize a pool pump and the answer is, yes, you can. By definition, a pump is too large for your filter when the pump pushes more gallons per minute (GPM) than the filter allows.

When this happens, the pump is pushing water through the filter faster than the filter can catch the debris. As a result, the debris ends up back in the pool.

Is Your Pool Covered?

High winds and run-off contaminants can add to the dirt that ends up in your pool. If you vacuum your pool in the morning and notice more dirt in your pool later in the day, you might want to consider purchasing a pool cover.

The pool cover will not only protect your pool from dirt, leaves, and other run-offs, but it also reduces your consumption of chlorine as well. In our opinion, it’s also a great investment when you’re ready to close your pool for the winter.

Do You Have A Leak In Your Return Line?

In an in-ground pool, you may have a series of three-way fittings that allow you to plumb in several returns. In an above-ground pool, there may be a header that feeds into the return line.

If dirt or sand is coming through the return line, there may be a leak in the return plumbing. In this case, we recommend using Fix-a-Leak or a similar product that finds and seals the leak.

I’ve Checked Everything Above

If you’ve checked all of the items above and you’re still experiencing a good amount of dirt and debris back into your pool, leave a comment below or you can ask our pool community in our Facebook Group or our INYO Forum.