Filter Pressure Keeps increasing Quickly

[MoDat]

Hey all,


not sure what's going on but I need some help.


So I have a 35k gunnite pool with a Pentair FNS Plus 60 DE filter. Most years I only need to backwash once or twice and I usually use the filter pressure gauge to tell me when to do this.


However, this year has been different. We opened the pool in May and by end of May the pressure increased 10PSI so I did a backwash and recharged it. As time as gone by I've noticed that I need to backwash and recharge it a lot more often and I am not sure why.


I took apart the filter on Sunday, cleaned the grids (they looked great) and recharged it again. I thought all was well but we got some rain last night and I went out to check the chlorinator and noticed that the PSI was 10PSI over its standard again.


Does anyone have any clue what can be causing my filter to need backwashes and recharges so often?


The pool looks great btw. Super clear and chemicals are on point. I also have a BETTA this year which has really trimmed the necessity to clean the skimmers and net the pool


thanks in advance for the help


Edit: I also noticed de by the pool heater. Not sure if it’s related or how de even got there. See pics here:

https://imgur.com/a/JTrSYJv

 

[Newdude]

Does anyone have any clue what can be causing my filter to need backwashes and recharges so often?

Because it's working great. Quick filter cycles are almost always a chemistry problem, not a mechanical one.

Overnight Chlorine Loss Test to prove it.