Yes BigDave, it does appear to be working, today after adding some DE I decided to hop in the pool with the vac and walk the pool very slowly and let my feet tell me whats down there lol cause I still cant see over 18-24" down. The bottom of my pool was very clean, only a few leaf stems and a couple slick spots but not slimey. When I vacuumed with that DE in the filter the pressure rose much quicker than just letting it filter on its own with the DE. The thing I cant figure out is I cant shake that green tint. My chlorine is holding at night, lose maybe 1 point, and get 0 to .5 on cc test. During the day I see about a 4-5 point loss. Been keeping the chlorine stil in the 20s. I want to say will the DE help with the greenish tint but I will say Can it help? lol I still wonder if all that shock with the .26% copper could have added enough copper to the water to get the green? if so would a sequestrant? help me