More time may be the only option?

[Lake Placid]

Today marks 3 weeks into my SLAM. The issue is the seams of the panels that makeup the pool walls are seemingly holding algae. Scrubbing yields no visible sluff off. The staining has lessened over time with 3 or 4 of the 12 seams clearing up to virtually no staining. I’ve hung socks with 73% cal hypo shock next the the seams to see if any visible change happened, and that was a no. Sadly the cal hypo dissolves too quickly. Scrubbing with said sock doesn‘t help much if at all. I’ve scrubbed with Trichlor pucks and same result, no real change in the staining. I’ve scrubbed with a standard scotch brite coated sponge dish scrubber designed to hold detergent filled with 12.5% liquid chlorine and no help there either. Also tried that method with 20 Baum hydrochloric in the scrubber to no avail. Scrubbing with a tile and grout brush initially removed some embedded organics (also removed the caulking from some of the seams - oops but it did reveal nasties that needed to be broken loose anyway). Any thoughts on a creative solution to attack this more quickly. Water has been and remains clear. Continuing to Slam at 16ppm (12ish is target with CYA at 30 ppm). Combined chlorine has been and remains elevated. Pics attached for reference. Love to hear any thoughts.

Stephen

 

[JohnT]

Welcome to TFP!

My bet is it isn’t algae, but a metal oxide. Algae will generally wipe away easily and your chlorine level would easily have it bleached to a yellow brown if it was algae. Try scrubbing with a vitamin C tablet, but the green color probably means it won’t work.

 

[Lake Placid]

I neglected to mention, I initially thought it was metal staining. Hit it with Vit C tablets and that didn’t touch it. I didn’t think it was organic/algae initially because it presented as old rust stains in look and the pool was clear with no visible blooms when I opened this year. Over time with CC levels elevated I believe I’m battling something organic. The only thing that has helped lessen the staining to date is time.