Adding DE to sand filter

Nj swimmin

New member
Jun 24, 2018
3
Nj
Pool Size
25000
Surface
Vinyl
Chlorine
Liquid Chlorine
I have been adding small amounts of DE to my skimmer to help my sand filter with some cloudiness. My question is, what is a safe pressure? Im normally at 18psi but with DE it can get up to 25psi before I get nervous and backwash the filter.
 

YippeeSkippy

Mod Squad
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LifeTime Supporter
Jan 17, 2012
19,051
Evans, Georgia
Does your gauge go to zero when the pump is off? 18 pounds of pressure seems a bit high to me for a sand filter without DE. For example mine lives around 12-13 without a dose of DE.
We recommend backwashing a sand filter when the *clean* pressure raises 25%.

Maddie :flower:
 

Nj swimmin

New member
Jun 24, 2018
3
Nj
Pool Size
25000
Surface
Vinyl
Chlorine
Liquid Chlorine
Does your gauge go to zero when the pump is off? 18 pounds of pressure seems a bit high to me for a sand filter without DE. For example mine lives around 12-13 without a dose of DE.
We recommend backwashing a sand filter when the *clean* pressure raises 25%.

Maddie :flower:
Yes it goes to zero. It was a new gauge last year. It used to run at about 12psi but I added a heater this year so I was thinking that may have caused the pressure increase. I might try another new gauge just to be sure.
 

Nj swimmin

New member
Jun 24, 2018
3
Nj
Pool Size
25000
Surface
Vinyl
Chlorine
Liquid Chlorine
Hi there Nj..... Were you following the instructions for adding DE? You only want to add as much as it takes to raise 1 pound psi.
Yes but even a cup of DE is raising the pressure to 25 psi. Last night I backwashed it again and tried a half cup and that was better at 20 psi. I let it run all night and this morning was at 22 psi.
It's probably ok.
My base level psi went up 3-4lbs after a heater was installed as well.
Yeah I have been seeing other posts with people that had the same thing happen after the heater install.