Filter grid gets dirty again in minutes

Jump to latest Follow Reply
P

PeteO

0
Jul 21, 2015
8
Austin, TX
The pool looks clean. The backwash looks clean. The chemicals look reasonably good (See below). Salt is lower than usual but still OK. The filter PSI is just above my upper range. (32psi) I open the filter and the off-white grids have become a beige, darker than I have ever seen in 10 years. It is a consistent beige, not spotty. I clean the filter as per usual and it easily cleans up. The PSI drops to 20 (my lower range), but in 15 minutes, it is 22, and in 2 hours it is at upper range again (30 psi). I open the filter, and it is that same dirty beige again. I can't keep cleaning, so I repeated the clean once per week for four weeks. The problem continues.
FC: 7.5 ppm
CC: 0
pH: 7.7
TA: 80 ppm
CH: 525 ppm
CYA: 51 ppm
Salt: 2726 ppm

What do you think? Do I just keep repeating the cleaning process? Could I have an algae and need to SLAM?
Regards,
Pete
 
Thanks for the info @PoolStored. Results of Overnight Chlorine Loss Test...
9:00PM FC: 8.5 ppm
5:30AM FC: 7.5 ppm

Unfortunately, being a 1.0 ppm difference and comparing to Loss Test instructions, this does not indicate an obvious next step. Considering that repeatedly cleaning is not helping, I will try the SLAM process. Thanks again.
 
The main problem is solved now. I had forgotten to replace the DE Powder after the last major grid clean. Then, when I saw PSI problems and re-cleaned, I forgot again! It's like I "relearned" the process incorrectly after doing it correct for almost 10 years. I think this explains why the PSI increased so quickly and why the backwash always looked so clean. With DE Powder replaced, the filter psi is now behaving as expected.

I probably need to replace the grids. They were already very old - somewhere between 11-17 years! And running for 2 months at high PSI and no DE powder certainly doesn't help. In about 4 grids, about a dozen plastic points along the spine are pushing through. For now, I am watching filter levels and for DE powder in the pool. I saw some white dust in the pool, but I also recently added salt, so I'll check repeatedly over the next few days before deciding if new grids are needed.
 
  • Like
Reactions: PoolStored
You must log in or register to reply here.
Top Bottom
Back
Jump to latest Follow Reply