Month ago back flushed my Pentair FNS Plus Filter. Bumped it once, then proceeded to add DE as usual. Noticed immediately that the water turned cloudy, and sure enough, the cleaner started picking up DE. I thought I may have a cracked filter manifold, so I tore it all down and cleaned, but there were no cracks or tears in the fabric. Re-assembled, and added new DE. Again, immediately noticed cloudy water from DE. This time I noticed the pump basket also had DE in it. What do I do now?
Another DE in the pool thread!
- Thread starter simplemind
- Start date
The first time, you may not have backwashed long enough so there was some DE in the internal plumbing that got shot into the pool. The second time.... DE in the pump is expected because you add DE through the skimmer. Did you bleed all the air out of the filter before you started adding DE? Because I could see the surging that usually happens as the pump primes and the air inside is expelled shoving DE through the grid. Multiport set to bypass instead of filter?
The only other alternatives are a crack, a torn grid, a bad multiport valve, you didn't reposition the bleed tube right, or the screen on the end of the bleed fell off.
The only other alternatives are a crack, a torn grid, a bad multiport valve, you didn't reposition the bleed tube right, or the screen on the end of the bleed fell off.
Thanks for the quick response! I did bleed the air at the top of the filter until water shot out, then closed the valve. Multiport was set to filter. Inspected the grids and manifold and all good. The bleed tube in place, and screen firmly attached.
I guess the multiport bad, or a bad seal could be the culprit, just dunno. Besides, I thought if the multiport seal was bad, it would just allow DE to seep back after shut down.
DE sticks to the grids pretty well. It generally doesn't seep out. It is normal to see a little puff of DE when you start the pump, however it should be small and disperse quickly. You could have a hairline crack somewhere that opens up under pressure. You can check the spider gasket on the multi-port valve and make sure it is stuck down tight and there is no excessive wear. If all appears to be good, try adding the DE very slowly in the skimmer.
A question...does the mesh of the grids wear out, ie will worn mesh allow DE to pass thru? My grids are about 7 yrs old, but physically they look fine.
If the weave on them is tight, no holes, then age shouldn't matter. If there are any frayed spots that could possibly allow DE to pass through.
Look very carefully at the grids. First time I looked I didn’t see a whole in the mesh. I was pretty sure there was one, went back over all the grids and found the hole
