I thought Vibrant was snake oil, but the more I saw about it... the more i realized it wasn't.
I would suggest trying that and running carbon. That will clear you up I'd feel certain. just follow the directions on the bottle. No telling what's really in it, but here is the back.
I tested salinity of this stuff and it measured 65ppt. Which is very high. Kind of weird for sure. It says there is a cultured bacteria blend in there in there, but it's that 3.5% of other ingredients that i wonder about. I would not be surprised if it wasn't some kind of algicide considering the salinity. I also tasted... it was of some weird salt like flavor. Somethin reminded me maybe of something like potassium chloride. It has no color or smell.
Anyway, I've not noticed any negative effects. It cleared the water and has really destroyed any nuisance algae in about 2 weeks.