Pool Filter Sending Dirt Back into Pool

[5MARC]

Not sure exactly where my chemistry is at the moment, but all summer I’ve been battling algae that I believe is coming from my stairs. I think I have that resolved, but the filter has been blowing dirt that I sweep up back into the pool. Replaced the internal plumbing in the sand filter this spring (not sure what it’s called) so I’m fairly confident that is in good working order. I’ve read other posts about gaskets & parts in the MPV needing cleaned or replaced. Please send any info or suggestions.
Hayward S180T

 

[Texas Splash]

You'll first want to confirm what is blowing back into the pool. Is it dirt, algae, or sand? Have you been able to collect any of it to see what it feels like? Sand will of course feel gritty. If it's dirt it may be soft, but with either one it could have something to do with the laterals inside. If it's algae then a SLAM Process is required. To confirm algae, you could do an Overnight Chlorine Loss Test. It would also be a good idea to post a full set of water test results just to be safe.

 

[5MARC]

FC 10
pH 8.0
CYA 0. ( haven’t been able to get a reading for a couple months. Even when adding CYA granules in a sock. Maybe 5#?) Could my CYA reagent be bad or ineffective?

I assume it’s algae coming back in. It’s not gritty and only shows up on first start of the pump, or during vacuuming when the pool bottom is getting a little green. Pool bottom looks green, but brushes of easily & in a cloud.

 

[Texas Splash]

Could my CYA reagent be bad or ineffective?

The R-0013 is usually one of the most resilient reagents. But everything you are describing on the pool floor sure sounds like algae. Looks like it as well. But you definitely need a CYA of at least 30. Your 15K pool would require 40 ounces of stabilizer to increase the CYA by 20 ppm. So assuming you have some CYA in there now, adding 20 more shouldn't be a problem and get you in the 30-40 area. You might try that before starting the SLAM Process. Also lower the pH to about 7.2 before you start.

 

[5MARC]

Will the CYA lower pH at all? It is acid after all. If not, I can go pick up some Muriatic acid later.

 

[5MARC]

CYA is around 70. Discovered I was using the wrong reagent. Still need to lower pH & sweep/brush until it’s clean?

 

[Texas Splash]

Will the CYA lower pH at all? It is acid after all. If not, I can go pick up some Muriatic acid later.

Not really. Much different than muriatic acid.

 

[Texas Splash]

CYA is around 70. Discovered I was using the wrong reagent. Still need to lower pH & sweep/brush until it’s clean?

Yikes! That's a bit different. Okay, no sweat, same process. Lower the pH to about 7.2 and increase the FC to "28" per the FC/CYA Levels. Good luck!