Hi i've just set up my old aqua one 620 and want to get it planted up as everything ive put in my main tank gets eaten by the occupants. Im slowly sorting out my stocking on that tank so i can start putting the plants i want in there. Anyway i want to get some CO2 going in there but which is going to make more sense for me on a 90litre tank? High tech or low tech? My main tank is a 300litre and will definatly have a FE CO2 setup but im not sure if i can get away with the yeast method on the smaller tank to save a bit of cash as high tech on both tanks is going to cost a fair few quid.