Love this forum so far and the invaluable information it has provided, as well as the unending help from other pool owners/users.
I have an old Apollo VA-38 DE filter with brand new grids (38 sq. ft.), a new o-ring, and a new pressure gauge. When there is no DE on the grids, the operating PSI appears to be 12-15.
If I add the recommended amount of DE to my grids (1 to 1.5 lbs per 10 sq. ft.), this amounts to 4-6 lbs, so I usually put in 5. No sooner do I do this when my PSI slowly rises to around 30-35, effectively doubling the PSI when there's no DE on the grids. The other result is very little water moves in my pool. The returns jets barely push out anything and the skimmer barely takes in anything.
However, when I put less than 5 lbs on the fresh grids, I find that they barely get covered, which defeats the purpose of having a DE filter.
I feel like I'm trapped. Please help!