9W in a small tank is not high light <wpg
rule don't apply to small tanks> ... I would think you have medium light <depends a lot on light & reflector>. You can try some higher light requiring plants, but you might not get great result.
Personally, I don't think CO2
is needed in the 2g. Yes, injecting CO2
will benefit all plants, regardless of light level, but there is diminishing rate of return with less light.
If you like playing with CO2
, by all means go ahead ... maybe half the recipe & use a 1l soda bottle. But I would think Excel is the way to go if you want to give the plants a boost.
is fine if you have $$$. You would need a CO2
bottle, regulator, & a reaction chamber (and optionally a pH controller). Expect to pay $300 - 500 for a decent setup.