Cartridge filters clogging every few days

[poweranimal]

So here’s the quick facts. Filter is 8 psi when clean, and I clean them at 18psi.
CYA is now over 200 (stupid me using tabs)
Filters are jumping from 8 to 18 psi every few days. Seems algae is forming on the filters. Pool water is crystal clear and has no issues.
Last time I soaked the filters in a trash can with a gallon of chlorine, but that was short-lived. After I put the filters back in last week, I shocked it, and doubled the chlorine tabs to 8 at a time trying to keep the chlorine above 15ppm.

Pool will be drained in a couple months and will be buying the RJ45+ SWG.

Is my CYA at a high enough point that the chlorine can no longer kill? If so, do I just start adding algaecide every week until I drain it?

Why is algae only growing on the filters but not the pool? That’s what doesn’t make sense to me.

 

[TinFoilHat]

If you have algae in the filter then it's in your pool too whether you can see it or not. It's time to SLAM if you do an OCLT and fail it. The CYA will need to be reduced though to accomplish it. Find the CYA/FC chart in Pool School for the relationship. Don't use any pool store potions to rid the algae, only a slam is the correct way to do that. A SWG is a great idea but you need to get your water under control and then make sure that your water parameters remain correct for SWG use. Dump your test strips for a recommended Taylor 2006C or a TF100 or TFPro test kit. Then post your numbers for a proper diagnosis. In the meantime while waiting for your test kit to arrive, put 1/2 gallon of liquid chlorine into the pool daily to keep it going for now.

 

[Dirk]

^^^^ What T said. Algae isn't forming in the dark inside your filter. Your filter is capturing algae from the bloom that is raging in your pool. You can confirm that with an
Overnight Chlorine Loss Test. Exchange water to lower CYA (FC/CYA Levels). Then the SLAM Process after you acquire a proper test kit (Test Kits Compared). Don't shortcut the SLAM. Follow the directions to the letter until you can pass the end-of-SLAM criteria. Shortcutting a SLAM will only result in having to start over.

 

[poweranimal]

^^^^ What T said. Algae isn't forming in the dark inside your filter. Your filter is capturing algae from the bloom that is raging in your pool. You can confirm that with an
Overnight Chlorine Loss Test. Exchange water to lower CYA (FC/CYA Levels). Then the SLAM Process after you acquire a proper test kit (Test Kits Compared). Don't shortcut the SLAM. Follow the directions to the letter until you can pass the end-of-SLAM criteria. Shortcutting a SLAM will only result in having to start over.

So the test I just did 5 minutes ago (yes, it’s with the Taylor kit mentioned) is as follows:
PH 7.7
FC 7
CC <0.5
TA 120
CH 250
CYA 200+

Makes sense if the pool has algae but the filter is just catching it all. It’s hard keeping the FC at 15 ppm to match the cya, especially when I’m trying to use the rest of the tablets before I drain it to get my moneys worth. Of course the more tabs I use, it furthers the problem.

 

[Bperry]

So the test I just did 5 minutes ago (yes, it’s with the Taylor kit mentioned) is as follows:
PH 7.7
FC 7
CC <0.5
TA 120
CH 250
CYA 200+

Makes sense if the pool has algae but the filter is just catching it all. It’s hard keeping the FC at 15 ppm to match the cya, especially when I’m trying to use the rest of the tablets before I drain it to get my moneys worth. Of course the more tabs I use, it furthers the problem.

The tabs will last forever so there’s no use using them all this season. Stop using them and save them for later when your pool isn’t OD’d on CYA any longer.

But yes to your question: the high CYA is making the chlorine unable to sanitize the water.

 

[Dirk]

So the test I just did 5 minutes ago (yes, it’s with the Taylor kit mentioned) is as follows:
PH 7.7
FC 7
CC <0.5
TA 120
CH 250
CYA 200+

Makes sense if the pool has algae but the filter is just catching it all. It’s hard keeping the FC at 15 ppm to match the cya, especially when I’m trying to use the rest of the tablets before I drain it to get my moneys worth. Of course the more tabs I use, it furthers the problem.

Put your test kit model in your signature and remove "test strips" if you want us to stop suggesting you get a proper test kit! And by remove "test strips," I mean from your life altogether. Toss 'em in the trash. They are less than worthless, because they can only serve to give you bad information. Don't try to get your "money's worth" out of those, you already lost that money when you bought the strips.

The tabs are destroying your water's chemical balance, causing your algae, and creating the need for semi-daily filter cleanings. Sidebar: cleaning cartridge filters is what wears them out more than anything else. Are any of those problems what you mean by "getting your money's worth" out of the tabs? (Sorry, a little tough love there.) As suggested, STOP USING TABS. Save them for sparse use, once in a while. CYA does degrade over time, so you can use the tabs someday (they'll last) for restoring CYA the next time it is low, or in a pinch when you want to leave your house and pool for a few days. Get your money's worth out of them that way.

Until you're willing/able to stop using tabs and exchange most of your pool water to bring the CYA down, there's not much else we can help you with...

Use the TFP Pool Math calculator, here, and the data from here (FC/CYA Levels) to calculate how much water to exchange. But prepare for some sticker shock. Assuming your pool really is at CYA 200, and not higher than that, we're talking in the 85% exchange range.

Do you know how to properly test CYA when it is suspected to be over 100? Or did you get that "200+" from strips or a pool store?

Strongly recommend you read this article, especial regarding the cautions about draining water:

Draining - Further Reading

www.troublefreepool.com

 

[Newdude]

especially when I’m trying to use the rest of the tablets before I drain it to get my moneys worth. Of course the more tabs I use, it furthers the problem

We see this often and I can never understand it.

Say I'm using fuel additives in my car and I find out they are harmful. Nowhere in my brain do I want to use the 5 other cans I have. I cease and desist. Maybe I'll use them in a different capacity one day, maybe I'll sell them and maybe they'll go in the trash. But using them once I realize it's problematic to get my money's worth is not part of the thought process.