Most Common Sand Filter Problems

Pool equipment

Your pool filter is important for keeping your pool looking clean and clear. It’s important to get regular pool filter maintenance and to recognize signs that something is wrong with the filter. Here are some common problems you may notice with your filter as well as ways you can help prevent it from failing.

Cloudy Water

Cloudy water is often a sign of algae in the pool, which means more shock needs to be added to the water. However, in some cases, the cloudy water can be caused by high pressure in the filter. If the filter is reading 8-10 pounds higher than the pressure reading after cleaning, it means that it’s dirty and needs to be backwashed. In many cases, the backwashing will get the pressure back to a normal reading, but if the pressure remains high, there could be some other problems. These include a bad gauge, bad sand, a problem with the multiport valve that’s recirculating water and preventing good backwash flow, or an obstruction either before or after the filter. If you’re having problems identifying the cause, a External link opens in new tab or windowpool maintenance company in Duluth can quickly determine the cause of high pressure and get the filter working properly again.


There are a couple places you may notice water leaking from your filter. After you backwash the filter, it’s common to see a small stream of water coming out of the backwash line. However, if the leaking continues long after you’ve finished backwashing, there’s probably a problem with one or move valves, O-rings, or spider gasket seals. Resetting these parts may remedy the problem or they may need to be completely replaced. Another place water might leak is from the filter tank itself. Unfortunately, a cracked tank can’t be repaired and requires replacement. Often, it’s more affordable to purchase a new filter instead of just the tank component.

Woman swimming in pool

Low Pressure

It’s important to monitor the pressure level to ensure the pressure is neither too high nor too low. When the pressure drops substantially in a short amount of time, it’s likely that the cleaner isn’t working at all, which means that the sand filter pressure is too low. This is usually due to a blockage on the side of the pump that uses suction. This problem can often be solved by replacing the O-ring or removing the blockage. In some cases, the pump is too small for your pool and you need to replace it with a larger one.

Sand in Pool

When your pump has a broken lateral, you’ll notice sand constantly leaking into the pool. The laterals are responsible for sifting out the sand, but if this part of the filter gets cracked or other internal parts break, there will be a substantial amount of sand on the floor of the pool below the returns. It’s important to remember that a small cloud of sand after backwashing it normal, but broken parts in the filter will release much more sand than this. Fortunately, replacing the set of laterals is a relatively easy task and your filter can often last a few more years.

Preventing Filter Damage

The best way to prevent filter damage is to maintain it regularly yourself and professionally. In addition, make sure the pump you’re using is sized right for your pool and that it’s properly winterized. To learn more about pump care, contact Sunrise Pool Services Inc. today.