Frustrated with a Clogged Sand Filter, 3 Things to Check – Copy

Does your pool appear very cloudy and even though you backwash, it’s not getting better. You may have a clogged sand filter.

To unclog a sand filter, begin by backwashing the filter. This reverses the water flow, forcing dirt and debris out of the sand.  When backwashing your filter, it’s important to not rush through each step.   It may be that the pool just needs to be backwashed and the filter isn’t clogged. 

If that’s not enough, consider deep cleaning the sand by using a garden hose to flush it out. Finally, ensure the filter is properly reassembled and that the air relief valve is opened to release trapped air.

 

Backwash the Sand Filter

When backwashing the filter, you need to turn off the pool pump and ensure the valve is set to “backwash”.   Then, start the pump and allow it to run on the backwash setting.   Then, shut the pump off and move the valve to the rinse setting.   Then turn the pump back on while the valve is on the rinse setting.   My practice is to rinse for a shorter period of time than I have the valve on the backwash setting.   There are larger filters that have the backwash and rinse in the same valve.   You don’t have to shut the pump off in order to move it to the rinse setting.

 

 

Deep Clean the Filter Sand

There are now products on the market that you can add to the sand filter that will flush out the debris.   When doing a deep clean on the sand, you first carefully remove the multiport valve from the sand filter tank.

 

If you see any large debris in the filter, then you should remove the debris before adding the solution to do a deep cleaning of the sand.   Make sure to follow the instructions on the bottle for dosing.  You want to add the right amount based upon the size of the filter.   Then you can use a large stick to mix the sand and the solution around.

 

Depending on the solution that you use, you should let the solution sit for several hours.   Then come back and backwash out the dirt that you are removing.    We recently did this treatment on a pool and the solution removed a significant amount of dirt and small debris from the filter.  

 

After completing the deep clean, make sure to properly reassemble the top of the sand filter.  Then, you can turn the filter pump back on.   You want to make sure before you turn the pump on, to check the pressure release valve to release any trapped air. 

 

• • Filter Efficiency
    Backwashing your filter on a regular basis, helps to ensure that the dirty water is being removed on a regular basis.   With residential pools, we usually backwash 1 to 2 times a month.   If backwashing a commercial pool during the swim season, we backwash once a week due to the higher bather load.

• • Failing to consistently backwash your filter can result in other issues long term. If a potential customer calls us regarding an issue with a heater or their pump, we often ask them, when was the last time they backwashed their filter. 

Professional Help

If you’re uncomfortable performing these steps or if you suspect a more serious problem, consult a professional pool technician.   Also, a qualified pool professional is going to be able to diagnose any issues and make a good recommendation on how to solve this issue.  Usually if your filter is less than five years old, it will most likely not need a sand change.   Filter sand medium should last for up to five years or more.