I've had co2 since day 1, the diatom and algae bloom was just due to new tank syndrome. Another day or two and all the algae will be completely gone. i kind of wished i took a before and after photo to see how much of a different the shrimp made on the diatoms. The only thing I'm considering doing with lighting is actually picking up a new system to increase light into the tank, because i'm not getting enough light to my rotala colorata. They should be growing red, but just getting green growth. Also, wished that the glosso would grow stems horizontally, but I think that's going to take along time, since they were tall stems which i first purchased them at ADA.