Yellow spots on pool floor

[purptiger]

Hello, it has been a while since I have posted. I have a SWG and I am wondering if it causing me a problem, I am getting yellowish tan spots on the floor of the pool. I have tried to brush them off, but they do not come off easily. Would a pumice stone work?

I went to the local pool store and they told me it is a yellow algae problem and I need to shock the pool. Is this some type of organic stain? My chemistry is pretty much in balance.

 

[Bama Rambler]

Post a set of test results.


Also it'd be a good idea to run the OCLT.

 

[purptiger]

tOK! Here are y readings as of this am,
FC 3.5
PH 7.4
TA 80
CH 350
CYA 70
86 degrees
I have borax at 50 and salt at 3500. I am running my SWG at 50 % for 10 hours.

 

[Bama Rambler]

Those numbers don't look bad. Have you had to up your swcg percentage or pump run time lately?

 

[duraleigh]

Adding to bama's question, do you have a tri-chlor puck you can place on the yelloe spot to see if it goes away. If it doesn't, do you know how to use vitamin C (crush the tablets up in a sock and hold the sock on the stain for a few minutes) to test for metals?

 

[purptiger]

No I have not had to change my pump time or SWG %. Any idea what the stains are? I need to try the puck idea or vitamin c.