I'm starting a new 75g planted tank. I already sort of figured out the substrate. However, I know next to nothing about CO2 systems and I have a 250 w Sun Systems Metal Halide pendulum light that I was using on another project. My first question is can anyone recommend a good CO2 system for a 75g tank?:help::help: And a good place to purchase it? my second Question is my Metal Halide going to produce the right light spectrum for a planted tank? if not what would everyone recommend for a tank this size?