Cartridge Filter PSI is not stable

voidpointer

Gold Supporter
Oct 8, 2020
579
Prosper, TX
Pool Size
19440
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Jandy Aquapure 1400
Hey folks, I was going to post this update in my original thread (linked below) but there's a banner at the bottom that recommends creating a new thread since it's over 60 days old. So here I am.

To summarize: I posted about my cartridge filter PSI being at 18 at 2500 RPM when my lowest recorded is 11 and usual PSI is 14-15. It was much colder and I was mainly asking if I could wait until it warms up.

Since then, I have cleaned the filters and unfortunately maybe a week or two after, it returned back to that 18 PSI.

I've noticed this over the years (pool opened in March 2023), that as I clean the filters, I have to start cleaning them more frequently and it becomes harder to keep the PSI low. The research I did a long time go on the forum basically suggested to do an acid bath, however given all the sand (which I detailed in the linked post), I'm not sure if that's the solution that folks would recommend.

At this point I don't feel that cleaning the filters every month or so will be an appropriate solution. What should I do?
 
Just maybe an OCLT is the next step for you. Glancing at your logs twice in the last three weeks your chlorine was less than 2,
Sounds like your filter is doing what its designed to do and filtering algae.
My CL has never been that low. I've also never had algae issues. Are you confusing the maintenance (SWG adjustments) with the tests? Like this?
1748023803304.png
 
It is the largest residential cartridge filter which is great.
One suggestion is to purchase new filters (it’s a quad setup) and then start fresh.
You can soak the old filters in a solution of TSP. Then you have an exchange set which makes cleaning your filter much easier and quicker.
See Cartridge Filter Use and Care - Further Reading
So something like this?

It's one of the brands recommended by the further reading page you linked.
 
Are you confusing the maintenance (SWG adjustments) with the tests? Like this?
Yes, when I viewed viewed the 3.5 and 4.0 three weeks to a month ago, followed by your SWG adjustment entry's coupled with cya at 40 its struck me as too low and not enough CL . Yes I entered your adjustment #, my bad. Good luck. Pete
 
Yes, when I viewed viewed the 3.5 and 4.0 three weeks to a month ago, followed by your SWG adjustment entry's coupled with cya at 40 its struck me as too low and not enough CL . Yes I entered your adjustment #, my bad. Good luck. Pete
Yep you're right, I do remember that. I let the numbers slip for a month or so, but got it back up where it needs to be. Thanks for checking!