hmmm, well the first thing you will want to do is go out and get yourself some quality water testing equipment. you will want to test for phosphate, calcium, ammonia, nitrate, nitrite, PH ans salinity. Those are just the basics. I would recommend the brand salifert.
The type of algae you have is called cyano...it is actually a bacteria. There are a few ways to get rid of the cyano. I would recommend better water quality and getting mroe flow in the tank.
What kind of powerheads do you have? How often do you do a water change?
You may want to look under the RB library for more tips on how to control pest algae.
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