What is causing DE to leak back into your inground swimming pool?

Answer 1

Simple. The filter is very old. You can count on at least 5 to 7 of the 8 grids to be bad ( having holes or totally torn) in a filter that old. Depending on brand that could be quite expensive. But still cheaper than a new filter.

Ken

Its not always torn or bad grids, inside your multi port valve there is a gasket called a spider gasket, (bout 20-30 bucks) it seals off the different compartments and when it gets worn, the backwash compartment or others can LEAK over into the filter position compartment, there fore letting some dirty and clean DE go back out into the pool, Very easy to replace, and VERY inexpensive fix compared to new grids and manifold. good luck.

David

Answer 2

The filter elements may be torn or damaged in some way, Proper assembly of the unit is very important. Air leaks, as this will cause the system to leak DE back into the pool. in case of air leaks, install a check valve between the pump and the filter valve.

Answer 3

Check your filter must be broken tailes or small wholes Don't quite know what "tailes" or "wholes" are but maybe the statement above is trying to say that you may have a torn filter grid(s) or a cracked manifold. The filter has to be opened and the 8 grids inside inspected for tears or holes even as small asan 8th of an inch can let DE back to the pool. Larger quantaties of DE indicate larger holes. Expect to pay in excess of $20 for a grid depending upon size. Don't be surprised too if you find more than one grid damaged.