Hayward ProGrid 72 sq. ft. Filter

[Seanhan]

MY ProGrid D.E. Filter say's to add 9 lbs of D.E. ( sticker on tank )
The book say's 9 lbs also, I have read from many sources that say 72sq ft needs 14 lbs ???
Who is correct ???

 

[jblizzle]

I would be inclined to follow the manufacturer recommendation in this case.
I think typical is 1 pound per 8 sqft; although I have also seen 1 pound per 10 sqft. Never seen the larger number you posted.

Remember after only a backwash you only want about 80% of the full amount also.

 

[Richard320]

Hayward. Use 9 lbs on a fresh fill or after manual cleaning. If you only backwashed, only 7.2 lbs. (80%) since it never ever completely comes clean with backwashing alone.