I have a 10,000 gallon gunite pool with a 48 sq. ft. Purex DE filter. I found a hole in one of the grids -- a tear in the fabric about 4 inches long. All of the other grids were perfect. Any idea what I did to deserve this tear? Aside from the one tear, the fabric looks pristine and even around the tear there is no degredation of the fabric. It isn't brittle or decomposed at all. I do a good job of keeping Chlorine in the 1-3 range with liquide chloringe and Ph between about 7.0 and 8. (Ph creeps up over this range over a week and I add acid to bring it down). I distribute the acid well and a long way from the skimmer so I don't think I have concentrated acid going into the filter. Any ideas?
BAF