Hi there, How would I find out how many sq ft my pool filter is? I’m new to this whole thing and we’ve just bought a new home with a 27,000 gallon rectangular inground pool. I have a Hayward 65 DE filter and when I have to backwash and re-add the DE powder, I’m trying to figure out how much to add and how to clean it. A bit overwhelming lol but I’m trying. 
Hi Kimmie91871,
For your Hayward EC65 27 Sq. Ft. DE Filter you will need to add 3 lbs. of DE after cleaning the DE fingers. Here is the Hayward EC65 Owner’s Manual and on page 5 of this owner’s manual shows the regeneration and cleaning procedure for your filter.
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