Thanks... I dose with Flourish Excel 3x/week. No other nutrients except root tabs.
Tank levels are balanced. HOB filter for a 50g runnning in the 36 g, so flow is good.
I will try doing a major clean with 50% water change?
37 gallon community; 10 gallon S-SS CRS; 2x10 gallon guppies; Specialties: Japan blue guppies (wild type), Ginga sulfureus guppies, Blond platinum LS guppies with purple mutation.
Non-aquatics: Off-track thoroughbred racehorse; 2 Maine Coon-type cats; 70 orchid plants.