I've had my tank for 8 months now and developed what looks like a brown algae issue. It's covering the plants and rocks and also on the glass here and there. Tank details are in my signature. I do weekly water changes (40% or so) and dose the plants with Flourish after water change. Two 15-watt bulbs on for 8 hours a day, which I just knocked down from 10.
Test results as of today courtesy of API:
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 20 ppm
Phosphate: 0 ppm
pH: 8.2 (we have hard water here in AZ)
Temp: 78-80 F (no heater...again, I live in AZ
Running a Hagen/AquaClear filter. Religiously change one of the filter media once a month on rotating basis (sponge, carbon, Biomax in that order). Any ideas what could be causing the algae and how to get rid of it? I just got the phosphate test today thinking it was that, but nope, it came out to zero. Thanks!