Pool Dust/Debris only when filter on

[budg580]

Hello - I've read numerous posts on this issue but I have not been able to find anyone with a final solution. I've been fighting this issue for 3 seasons here in CT. I have a SWG 15x30 above ground pool. All hoses are flex PVC and have been replaced with new flex PVC this season. Have 2 filters that I've been interchanging too. Hayward Cartridge and a Pentair DE. Same issues appearing. Have taken the SWG out of the pool plumbing too and have been chlorinating with both liquid and sometimes cal-hypo to sanitize.

Here's the issue in a nutshell: I get a brown dust like debris in the bottom of the pool ONLY when the pump is turned on. This debris happens within 2 hours of my 8 hour pump cycle. Doesn't matter which filter I have installed so it's definitely not DE returning. IF i chlorinate the pool with liquid chlorine and turn the pump off for 36 hours, there is no debris. Water is perfect. As soon as I turn pump back on, debris returns in 2 hours. Only method I've viewed that people have successfully used is to install a tube sock over the return jet. I've done this and it absolutely catches any debris and bottom of pool is perfect until the sock rips and then debris returns and time to replace sock.

The sock is a bandaid and a temporary fix. Need help in figuring this out before I replace liner and water. If a sock catches the debris, you would think the filter should. There's no way a tube sock can filter out smaller particles than a filter so the debris must be occurring after the filter. There's only the return line and the return jet that the water passes after the filter. All these parts have been replaced with new parts and problem still exists. So now it must be chemical right??

Chemically here are my readings: [email protected] FC@4 TA@100 CYA@50 CH@200

What is causing this debris to become present only when the water is under pressure by the pump? I should mention too that I've eliminate the pool steps which is filled with cement from the equation because I've completely removed them. Again, this issue does not happen when pump isn't running or a sock is on the return jet which eliminates anything airborne. If airborne or present in water, you would think it would occur even with pump not running and pool being used.

HELP PLEASE !!!!

Thank you -
Anthony

 

[welbo]

I think your logic is right on. I would not assume that "running either filter still causes the debris so it must not be the filter" is completely true though. From what I read, it sounds like the filter is the only likely cause.
I can relate my experience with DE and a sand filter to your problem. I put a small amount into a new sand filter to 'polish' the water. Every time I ran the pump, I got this brown dust on the floor of the pool. I could vacuum it up easily enough but it would come back. Fast forward and I learned the sand I used wasn't right and my filter wasn't working so the DE (and anything else) I put in it was passed straight through to settle out in the water.
In your case, I would think there could be some residual DE in the lines that gets out even after you swap to the cart filter. Or perhaps the cart filter has a problem, isn't seated right, has a hole, or something allowing it to leak. But based on what you wrote, I'd put a very high percentage chance that the problem is in the filters. I am no expert on either of those filters. When I have a problem like that, my solution is usually to take it apart and look closely at everything then put it all back together, making sure I follow directions as precisely as possible.