This just doesn't seem possible...

[ddegentesh]

So last season, I needed to add a touch of CYA, and I did so by very, very slowly adding it to one of the skimmers. Imagine my surprise when a minute or so later I started seeing little white granules coming out from the return. I thought that certainly was indicating a rip in one or more of the cartridges. They aren't terribly expensive so I bought a new set to install this season.

We opened yesterday, I installed the brand new cartridges, and sure enough, I needed to increase CYA just a touch. So again, I added it very slowly to the skimmer, and again, little white granules start coming out the return.

In neither case was the volume of granules equal to what I put in. Just a few here and there, but clearly visible and noticeable.

How is that possible?

It's a Hayward Swimclear C4030

 

[mas985]

The cartridges may not be seated properly and so debris is leaking by. Also, it could the air purge tube. There is a screen over it but sometimes those degrade and allow debris past.

 

[ddegentesh]

Thanks. Is there a suggested method for confirming the proper seating of the catridges?

 

[mas985]

I will gently rock them back and forth to make sure they are bottomed out. The manifold should also be flush with the cartridges.

But check the air tube too. That is a likely source of the issue.

 

[kimkats]

I will also add that here at TFP we have found through many real life testing and trying that it is MUCH better to put the CYA in a sock and either hang it in front of a return or put the sock in the skimmer basket (using care to not block the water flow) and let it dissolve that way. Once it is all dissolved use your target amount as you CYA level. You can squeeze the sock to help it dissolve faster. You do not want it sitting on the bottom of your pool as it can cause problems.

Kim