I have recently planted out a 400 litre tank with some relatively undemanding plants - swords, hygrophila, vallis etc etc. I wanted to have this tank co2 injected and opted (somewhat inadvisably) for the carbo plus system. After much discussion on the american planted tank forum and research on the net it turns out this product is extremely suspect in what it claims to do, and is in no way adequate for a 400litre tank anyway. I decided to trade this in for a pressurised system. Again further research has revealed that the 600gm bottle that i ordered with my D-D co2 kit will not last a month in my tank. I also run an eheim wet/dry filter wich will effectively outgas a lot of my co2! Therefore a 600gm bottle a)isnt big enough for the tank size anyway and b) wont last long at the ridiculous bps rate i will need to keep my drop checker showing green in a wet/dry filtered tank. My question(s) is this then: Is there no hope for me achieving adequate co2 levels without resorting to large scale FE usage and risking life and limb in the process?!? Or harbouring a potentially lethal missile in my house? I cant be bothered with the hassle of changing a 600gm bottle every month - not mention the cost? Could i change to just using seachems flourish excel as a source of carbon for the plants? At 2.7 wpg i am practically running a low tech lighting regime anyway? I use a eco-complete substrate. So with decent fertilisation routine and moderate lighting i would have two of the three boxes ticked? Anyone know if flourish excel is decent alternative to injected co2?