I know exactly what you are talking about actually, I've seen it a lot. The reason why it occurs in high flow areas is because that is where there is the most amount of nutrients is passed through, so it can very quickly develop in those areas.
Awesome so what than? Lol i have a reactor that was given to me but i am not using it. Would carbon or GFO help?
It cant be feeding.. I feed sooooo little. I feed nothing for my corals but light from my radion. And my fish get a tiny bit of spectrum sinking pellets and every other day a snall amount of mysis shrimp and i try and feed it slow through a turkey blaster so that i see them eat everything.