Cartridge Filter Question

[DThompson55]

We have a sta-rite cartridge filter that I suspect is a problem. First day opening the pool, my wife got in and started vacuuming. That's when I noticed the return water was looking kind of murky, as if the stuff she was vacuuming was passing straight through. I took the filter apart to make sure everything was seated right, and it was. The filter looked relatively clean, very little build up. So I'm not sure what's going on. I know next to nothing about pools so any advice is appreciated.

 

[Texas Splash]

Can you post a pic or two of the equipment pad? It would be good to see everything.

 

[DThompson55]

I'm not sure what pad means? But here's the pump and filter. This filter is a PLM100. The grit you see around it is undesolved CYA granules. I think I'll switch it over to a PLD50, which I keep as a spare. The PLD50 needs DE and needs to be cleaned more often, but it does a better job of filtering. It's possible the PLM100 has something wrong with it.

 

[Rancho Cost-a-Lotta]

Curious, how long ago did you add the CYA?

 

[DThompson55]

Maybe 2 hours before this photo. I did the CYA, pH, and alkalinity first. Then two hours later wife got in and started the first vacuuming of the season. I guess I'm going to assume the cartridge has a defect and toss it. I don't think I should be seeing any dirty water coming out the return. The DE cartridge is working fine.

 

[Rancho Cost-a-Lotta]

Maybe 2 hours before this photo. I did the CYA, pH, and alkalinity first. Then two hours later wife got in and started the first vacuuming of the season. I guess I'm going to assume the cartridge has a defect and toss it. I don't think I should be seeing any dirty water coming out the return. The DE cartridge is working fine.

Thanks for the reply. CYA granules getting stuck in the filter and may days to dissolve. No problem if you have time to wait, but if you clean or backwash the filter, you lose the CYA. TFP recommends using the "sock" method for adding CYA:

Solid/granular cyanuric acid (CYA) should be placed in a sock and the sock put in the skimmer basket or suspended in front of a pool return. After adding CYA you should leave the pump running for 24 hours and not backwash/clean the filter for a week. Squeezing the sock periodically will help it to dissolve faster. Test and dose chemicals in your pool assuming the amount of CYA added is in the pool according to Pool Math. CYA can be tested the day after it is fully dissolved from the sock.​

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The cartridge looks pretty beat up...maybe a tear?