Problem: Bad Grids or other Internals
Symptom: DE Filter Powder Returning to the Pool
If one of the parts inside the DE filter goes bad, it is immediately
obvious because DE will be returning to the pool. Always keep an eye on the filter returns after recharging the filter just to make sure nothing is coming
back to the pool.
There are several problem areas that can cause DE to return to the pool:
Torn Filter Grids – these
are usually pretty easy to spot when washing down the filter grids. Holes can develop anywhere in the fabric of the grid. Don’t forget to look at the
very end of the grid. Many times a hole will develop on the bottom of the “tube” of the grid.
Broken Manifold – a
cracked manifold will cause a large amount of DE to return to the pool
Broken/Missing Air Relief Strainer – if
the air relief strainer is broken or missing, it will allow DE back into the pool.
Broken Filter Necks – this
can be a tough problem to detect. If the neck of the grid can squeeze together easily, then it will not fit snugly into the manifold and will cause DE to
bypass, especially right after the filter is started up.
Bad Backwash Valve
– if the DE is bypassing the filter, it may be caused by problems inside the valve. Disassemble and inspect the valve.