I was wondering about the same set up. I have the 20oz CO2 tank, the
regulator, and the reactor. I use the power vortex reactor
(http://www.plantguild.com/html/power...x_reactor.html) with a yeast
brew. The reactor is awesome. I purchased the regulator off of ebay
and the tank I have from my paintball days.

The problem I've run into now is the sleeve on the regulator is too
large for the for the 20oz tank. I don't know if there is an adapter
of any sort and could not find one. So I kind of left that project
dead in the water. I also do not know if the 20oz canister will
provide enough pressure to even register on the regulator.

If anyone has any info it would be greatly appreciated. I am tired of
mixing yeast every few weeks.