I have a 60 gallon tank, with a wet/dry filter,cpap 1800 pump, a marine pro in sump skimmer, and a koralia power head. Has been running for about a year now, coral showed no side effects. Have a brain, devils hand, cocoa worm, green star polyps, some palys, lot of mushrooms, daisy coral, chili pepper coral, and some green zoas. Of course I did not check levels afterwards,(that would be too easy), was too late that night and worked again next day. All water tests prior have been fine.