I just moved my 55 gallon tank, to my 90 gallon tank. I've had my 90 gallon running for about a week, and I'm starting to see some brown algae growing on the sand and powerheads. I have to Aqua Clear 802's in there now, but going to be replacing them with 2 Koralia 850 gph. This is a FOWLR system, with 2 clowns, and a yellowtail damsel as my only fish. Unfortunately, I'm using tap water, but I checked my Phosphates and Nitrates and they both read 0. Is this brown algae an early stage of cyno, or is this just a normal maturing process of a new tank?