Sand or yellow algae?

[bbarn]

Hi there ,

First time pool owner here. I really can't tell if it's one or the other as when I brush it just goes into a cloud. These brown yellow spots just appear on the bottom of the pool, usually along the seems of the vinyl, some in other areas.

I am actually in the process of a slam with the chlorine being @ 10ppm, pH 7.6 and alkalinity of 110. Should I upkeep the chlorine level, re vacuum and increase the speed of my pump? Or look into maybe a broken lateral in the sand filter.

Thanks in advance.

Brian

 

[Texas Splash]

Welcome to TFP! If it's sand you should generally know right away by its texture. You can also try placing a thin sock or nylon over a return jet to try and see if you can catch any sand from the filter. Algae could be soft or slippery.

You mention doing a SLAM but didn't tell us your CYA to ensure you are at the proper FC level per the FC/CYA Levels. Do you know your CYA?

 

[bbarn]

Hi, my cya tested at 40

 

[Texas Splash]

cya tested at 40

In that case, your FC should be at 16 for an effective SLAM level. If you rule out sand, then continue with the SLAM Process and maintain that SLAM level of 16 for best success. You should see improvement, but if not, let us know.

 

[MWC]

Having a similar question. What I’m catching is gritty but it behaves like algae (clouds up quickly.)

 

[bbarn]

Good news it was not algae but sand so might have something going on in my sand filter. Will probably inspect it next season as I'm not running the filter 24/7 anymore and thus less sand in the pool now.
Thank you
Bri