YES! tehehe just kidding. I totaly agree with the others, you dont NEED co2 to have a nice planted tank, but you will have a harder time with algae, and plants wont grow fast and in a very good shape/condition, and plants may not be as green or colourful as they would with co2. I have a 250L planted tank, which has ground ferts and sand as substrate, and only has 2 36W t8 tubes.No co2 This tank can grow a hell of a lot of things. I have stargrass, rotala macranda and rotala walichii, leapord sword, amazon sword, marbled sword, tiger lotus (both of the latter constantly sending out babys) a hairgrass lawn, tennelus and probably others that i ahve forgotten. I get outstanding growth, with the tiger lotus sending out a new leaf every two days! I am getting another two tubes, and am getting a pressurized co2 system soon, only because i want faster and better plant growth, and want to get the plants pumping to out compete the bl00dy algae!!!
HTH