Go with home brew yeast reactor CO2. In a 10 gallon it's perfect, and relatively inexpensive. Get some 26 watt compact fluorescent spiral bulbs for the incandescent hood it probably has and you're on your way. I'm going to start EI dosing my 10 gallon in a couple days as I just set it up with plants this afternoon and gave the rooted plants each a bit of plant spike to get their roots feeding again. After about 3 hours under 104 watts of 3100K(approx) and healthy CO2 levels the eriocaulon and little stem plants are already pearling.