I am running a DIY ats. Currently it has dark brown/somewhat greenish color on the screen. Is this the type of algae I want to cultivate? Should I be getting GHA on it instead or maybe go to the local fish store and ask for some GHA from their stock?

Sorry if this question is answered somewhere else on here but I could not find the answer.

What type of algae should we be growing that's best for an ATS?