Hayward Pro-Grid Vertical DE Pressure

[Eriky]

Hey everyone,

I have a 2 year old Hayward Pro-Grid DE filter that I just turned on for the season, the past two seasons my pool builder opened for me, so this was the first time I opened myself.

I have a 30,000 gallon gunnite pool in the northeast.

My chemistry is pretty good, a touch high on the PH, but I just put in some MA.

My concern is the PSI is reading about 12-13 immediately after cleaning the grids, backwashing pre charge.

That seems really high, and the pool store I buy chemicals told me I never want to let my DE filter go above 15 PSI. That means I have basically 10% increase in pressure before backwashing.

I read the manual and it does not mention starting or ending pressures, only 8-10 PSI higher than a pre-coat.

That would be in the 20-23 range.

I am a bit confused on this. Do I have a problem with my plumbing? I checked my skimmers and they are clean, is my pre-charge PSI of 12-13 OK and my pool store is wrong.

Can anyone shed some light on this for me with regards to DE and my system in particular?

 

[Richard320]

12-13 sounds pretty reasonable to me. A lot of it depends on how big a pump you have, how long the lines are, and how many returns you have. There's no pressure regulator, so there's no way anyone can make a blanket statement about what your pressure should be. The pool store is wrong. Period. If you start at 12, backwash at 15. If it's 13 after you coat the grids, backwash at 16. That's a 25% increase. You'll start noticing a decrease in flow if you wait for 8 psi rise. Don't panic if it seems like your gauge never rises, either. Many of us can get by with an annual cleaning.

 

[Eriky]

Richard, thanks much for the reply. What you say makes sense regarding other factors. Thanks for easing my mind.