Discoloration showing up near bottom drain, what is it?

[zataralos]

Hi Everyone, a few days ago I started noticing a weird colored ring around the bottom drains. What caught my eye was that half of the circumference is dark blue and the other half is yellowish and both drains have the same appearance in the same direction. As background, my pool was experiencing high chlorine for a few days (10ppm), due to a combination of tricolor tablets and SWG cell (cell was going bad). PH and alkalinity have been in range but calcium hardness very low. I drained some of the water and refilled using hose-water to lower the chlorine We had a series of rainstorms that week as well. Not sure if any of this is a contributor. I read online that discoloration can happen when there are too many minerals present in the water. Before I head down that path, figured I'd get the experts to way in.

Btw - Chlorine is still high (~10ppm), PH is 7.8 and Alkalinity is 80. I've just added Chloru-Neutralizer from Leslie's and shut off the cell (got a new one) until it comes down in range. I have a gunite/plaster pool. Any thoughts on what's causing the discoloration and how I can prevent and restore it would be greatly appreciated.

Below is a picture of the drain.

 

[mknauss]

You keep saying your chlorine is high. What is your CYA?
Why add a chemical to lower chlorine. Unless your CYA is near 0, a FC of 10 is not an issue.
How are you testing your water chemistry?

I cannot see anything with the picture. But the colors you state could be copper. Have you been adding things with copper in them?

 

[zataralos]

Thanks, CYA is pretty low, might as well call it zero. I’m using a chem to bring it down quicker, kids are wanting to go in, I don’t think it’s going to drop that much on its own. I had my water tested at pool store (Leslie’s). Copper came back 0.

 

[mknauss]

You need a proper test kit, see Test Kits Compared. I suggest the TF-100 A proper test kit is needed to get the accurate water chemistry results needed to follow the TFP protocols.

With little to no CYA in pool water, the FC has a half life of 50 minutes when sun is shining on the pool water.