The pool belongs to a home owners association and I am a home owner who takes care of it. The pool is L-shaped and holds approx. 38,000 to 40,000 gal. of water. It is not open right now. We just bought 25 pounds of DE. I have never worked with DE but assume you put it in the sand filters. Correct? If yes - we will put it in this afternoon, because I need some help doing this.