Efficient DIY CO2 Diffuser?
I am setting up a 2.5G, and I will be using DIY CO2. However, I can't find a good diffuser. Can anyone recommend a diffuser plan that is:
-Requires parts available at big chain stores (petsmart, petco, etc.)
-Small enough to fit in a 2.5G tank
-Lasts a long time (no limewood airstones)
P.S.: I can't find the Hagen Elite Mini Filter anywhere.