Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Did not get good CO2 production out of these (I got 2 when I bought used tanks).
I get much better production with a 2 liter bottle, DIY set up. I used the same recipe in the little bottles, but it just did not work well.
For a 30 gallon tank I would set up 2 x 2 liters and rotate when to re-do them.