Sand filter shooting sand back into pool

[syedsam]

Turned on my pump and suddenly noticed small grains of sand collecting at the bottom of the pool. Never happened before. Do I need to replace the whole filter or is it something minor?

 

[Silvestor]

I had the same issue and ended up replacing the laterals fixed it right away without changing the whole filter.

 

[John Faulkner]

Could also be too much sand or wrong grade sand was added. Make sure it’s #20 silica filter sand only.

 

[Manikshaw]

Usually means a broken or cracked lateral inside the filter. You’ll need to open it up and check.

 

[Olivia Reed]

If sand is appearing in your pool, the culprit is usually a damaged lateral at the bottom of the filter. Even one small crack can allow sand to pass through and get pushed out with the water. The best approach is to turn off the pump, open up the filter, and inspect all the laterals. Replacing only the broken ones usually solves the problem, no need to replace the entire filter. While you’re at it, double-check that the sand level is correct and that you’re using the proper #20 silica sand, too much or the wrong type can make sand movement worse.

 

[Robert Smith]

This usually points to a broken lateral or standpipe inside the filter. Even a small crack can let sand escape into the pool. The best move is to turn off the pump, open the filter, and inspect each lateral carefully. You can replace just the damaged pieces rather than the whole unit. While you’re in there, make sure the sand level is correct and that you’re using the proper #20 silica sand—too much or the wrong type can worsen the issue.

 

[John Smith]

If sand is showing up in your pool, it’s usually a broken lateral or standpipe inside the filter. Turn off the pump, open the filter, and check each lateral. Replacing only the damaged piece usually fixes it. Also, confirm the sand level is correct and you’re using #20 silica sand, too much or the wrong type can make the problem worse.

 

[Henry Thompson]

I’ve seen this happen before when the multiport valve gasket was worn out. If that rubber seal inside the valve starts leaking internally, it can let a bit of sand slip through to the return line even if all your laterals are fine. It’s easy to miss because everything looks okay from the outside.

If you open the valve and notice any cracks, flat spots, or pieces of the spider gasket lifting up, replacing it usually stops the sand from coming back into the pool. Worth checking before you dig into the filter itself, it’s a cheaper and quicker fix if that’s the culprit.