I haven't decided which I'm going to do yet. The atomic diffusers that were recommended come in sizes ranging from 45-65mm with 5mm increments. Does it matter what size I get. Is that determined by the size of the tank or the CO2 needs of the plants in the tank? I have hygro, rotala, ludwigia, crypts, anubias, and some sort of grass-like plant that I don't know the name of 
