Failing plaster cause of algae?

[xxZH]

I’m having reoccurring issues with algae, which I think may be due to the poor condition of my pool. The pool has plaster which is failing in multiple paces (large pieces separate and fall off from the original surface below). The failing plaster seems to have been painted previously as well, and that paint is also failing and flaking when brushed.

I was out of town a few weeks ago and came home to a slightly green pool. I started the SLAM, finishing it this past Tuesday. The OCLT was less than 1, and the pool was clear. The pool stayed crystal clear for about 5 days and began turning green again on Sunday.

My CYA is 40. FC when I noticed algae was 10. CC was 0.

I’ve started another SLAM, but I’m a bit concerned it may be futile. Assuming the failing to plaster is just harboring algae, can I mailtain the TC level higher, closer to shock level until we get the pool resurfaced? Or does anyone have another theory to support why I keep getting reoccurring algae?

 

[ajw22]

You need to search for where algae is hiding in your pool. Could be in cracks in your plaster that your brush cant get into. Algae will form a biofilm that brushing needs to get through for the chlorine to be able to kill it.

You are aggressively brushing all pool surfaces during the SLAM Process?

One person found algae in a floating pool thermometer in his pool. Check around your light niche and any steps.

 

[Jannylee53]

Good idea about the thermometer.