I test phosphate with salient phos test kit and nyos nitrate test kitWhat are you testing with? This is just my opinion and what worked for me. Although your tank is new, start dosing neophos and neonitro. Start sparingly tho. Pull the rocks out with algae and scrub as clean as you can. Up the clean up crew and cut back on the water changes just a little. Hopefully your not dealing with dinos from the low phosphate and nitrate levels. And as others have said, cut back on the white light and the length of time the lights are on. I went with all blues for a few weeks and it helped weaken the algae before I scrubbed the rocks. I hope this helps.