I have two 96 watt pc's over my 55 gal tall, no CO2 additions. Plants are almost all covered in brownish algae, except for the leaves covered by other leaves. Those look the best, nice and green and healthy. Lights are 10000k and 6700k. Is this too much for no CO2 injection? I was trying to keep the whole thing very simple. could I just get rid of one of the lights? Thanks