Just when I thought I had the algae cleared

[jark87]

I recently completed a SLAM due to an algae outbreak. Water is crystal clear and passed OCLT a few days ago. FC is currently at 14 as I have been letting it drift back down. I was preparing to put the cover on and noticed algae growing in the grout lines between tiles, but above the water line, in the spa. See picture below. I’ve scrubbed the algae off and assume the the FC of 14 will kill what fell into the pool.

Should I SLAM again? We have rain in the forecast for tomorrow, so I want to get the cover on before lots of leaves get knocked down into the pool. Since water is clear and passed OCLT test, would it be safe to SLAM, but skip the brushing and vacuuming parts? I really don’t want to put the cover on only to have to take it right back off.

Thanks for the help!

 

[duraleigh]

Rather than SLAM, I would suggest you fill a spray bottle with 50/50 chlorine water mix and sray the affected areas. Probably not more that two occasions and the algae will likely be gone. That said, you may have some staining in that area......not sure

That sorta' looks like black algae. Can you scrape some off with you fingernail and smear it on white paper and it turns a VERY dark green?

 

[jark87]

Thanks for the response. It was actually a much brighter green than what is shown. Shadows make it look darker. I scrubbed it off with bleach, giving all of spa tile a grout a good scrub above the water line. I have the cover on, but will watch that area closely, as it’s easy to unhook the spa anchors.