Originally Posted by Walking_Target
Actually, I have and I still wondered about this, as my setup could be considered 'low light'. Given this and the way the EI method works, I had wondered if injecting CO2 for a tank that size and with that level of lighting would even be worth it.
I mean, I would see a good reason to inject CO2 if I had broken the magical '2wpg' (and yes, I know that wpg is not a great measure of lighting!). I simply want to get the most out of the EI method with the lighting that I have.
Well, from what I understand and I don't want to speak for Tom Barr, Tom has indicated that c02 in low light tanks never hurts and may benefit plants even in low light tanks by providing them with a necessary carbon source. Also, you don't have to worry about hitting optimal or ideal c02 levels in a low light tank for fear of your planted tank going to the dogs. Some people just use Seachem Excel than bother with c02 at all. Others don't do this and go with pressurized or DIY c02 as they want to keep Excel sensitive plants like elodea, riccia, vals, etc., that they find melt with Excel dosing. Others don't care either way as the real difference that you may notice with c02 injection or Excel dosing is slightly faster plant growth, but most people who setup low light tanks are happy with slower plant growth and so don't really care.
As far as learning about EI with planted tanks, that is a whole seperate issue. There is no black and white rule about how much and how frequently you dose as per EI regime. Full throttle EI implies that you have a high light, high tech, with pressurized c02. This is where you can see EI at its best. With low tech tanks/low light tanks, plant requirements for nutrients especially where you use a nutrient dense sediment should be a lot less. So, you can either use EI modified. Use the same macros and micros but fine tune or tweak them to work with low light, or use any other fert method that suits you again tapered down to the fact that you will be dosing far less for a low tech tank. And to further confuse the issue, I know people who have low light tanks with nothing more than inert pool filter sand that have been running for years. The tanks are fully stocked and they fertilize perhaps once a week, relying on the fish waste to provide needed fertilization. Lol, whether you agree with that approach or not, it seems to work for them.