If I'm getting new plant growth, is that a good sign of water quality? I have had my tank running roughly 13 days now. I have three plants, two java ferns and one amazon sword along with two baby zebra danios (coming out soon). I tested today and have readings of; ammonia - 0 and Nitrite - 0. I am now starting to see brown algae, can I now add a couple Oto's?