Is that the little bucket of compost?
On one hand, it's nifty.
On the other, it's not controllable, it stinx to high heavens, the refills are outrageously expensive, and you don't get nearly the boost you would if you shelled out the same amount of $$$ on a tank and regulator that you'd spend on the bucket and a couple refills.

Tanked CO2 remains the most economical way to enrich your atmosphere. Lock down your technique and setup before considering adding CO2 otherwise you are wasting your money, no matter what you're running.