Quote Originally Posted by aylad View Post
Carl and Poconos, when they use DE in their filters, only add enough to increase the pressure by 1.....I'm thinking they add about a cup, but I'll have to check on that. I would backwash the filter, notice your pressure reading, then add about 1/2 cup of DE and see what that does to your pressure. If you put too much in, you can always backwash it out.

Edit: Here's a link to CarlD's procedure. Hope it helps!
http://www.poolforum.com/pf2/showthr...g+sand+filters

Janet
Start with 1/4 to 1/3 cup. Wait 20-30 minutes after adding it and check the pressure. Enough to raise it 1 to 2 lbs, max. If you don't get a full lb increase, add a little more. I use about 1/2 cup myself.

If you use to much you'll see drain and return pressure will drop and the dial will go up. Simply backwash to clear it out.

You'll need to add more DE after you backwash--every time. But don't worry--I'm still on my first 10 lb box after 3-4 years!