Ya'll I have this grimmy, dirt looking crap in the bottom of my pool. Yesterday I used my little catfish vac and got it all up (so I thought) this morning I went outside pool looked great (patted myself on the back) my pool filter comes on at 3 in the afternoon so I went out there about 3:30 darn it! There was that crap again! Could it be dirty sand well not sand could it be dirt that is not settleing in the sand filter? Sandpro 3/4 horse-21x4 above ground. Help please I am way to annal to have this stuff in the bottom all summer.