I just got an aquriam about a month ago its a 20 gall. It has good filter good aeration excellent chemical ph ect. levels but there is brownish redish algae looking stuff splotched all over my fake plants and walls and everything. Is this good does it meen my batcteria is forming so i can add fish what does it meen. by the way there is 1 red wag platy in the aquriam