SLAM - Might be Mustard Algae?

[red-beard]

He is in Central America, it could very well be mustard algae.

Alan, the OCLT is the telling factor. If you lose FC overnight, something is eating it. There are organics still reacting. Have you cleaned the filters?

 

[ajw22]

CYA=35ish).

BTW, we round up. Your CYA is 40. You can’t measure 35ish.