Ok. I have a question now. If algae spores are "airborne", then does that mean that my neighbor's refusal to run his pool filter regularly and his "swamp" next door can be affecting my pool? (he opens in late June, has one party then lets it go green. Runs it in August has one party and closes it green). Because I am religious about testing and maintaining the water!! But since he let his pool "go green" last week, I've started having issues. Last night I repeated an OCLT because I thought something seemed off and I lost 2.5ppm for the first time since last July of last year. I had a SWG but it died so now I'm using BBB. I open the pool in April and close in October. Just had to ask.