I recently started converting my 10 gallon quarantine tank into a display tank that I intend to plant. As of right now, I only have about 3 feet of Hornwort in the tank, to provide a little cover for the dwarf gouramis im currently keeping. The light on the tank is a 15 watt fluorescent, which claims to yield the equivalent of 65 watts of light. I have an airstone in the tank, but I'm currently not using it.
So I've got two questions.
1) I'm planning on adding at least one more plant, probably a crypt, and a few small tetra tomorrow (the gouramis will be going to another tank). Will CO2 become a neccessity at this point, given the "65 watts" of light I'm getting?
2) Will I need to begin using an airstone with the addition of a small school of tetra, or will the two plants be producing enough oxygen to sustain them until I add even more plants. There is a small amount of aeration through the HOB filter, also.