Don't forget the fill...
You'll find the CO2 cylinder so much easier to work with, so much more reliable and so much safer. There are so many things that can go wrong with the yeast mixture set up it's spooky. You can find a needle valve at Peerless Eng. in Burnaby for about $23 PN KLN230B. I had adjusted my CO2 flow to about 16 bubbles per min if I remember right. That lasted a good long time on a 90 gallon tank dripping 1/2GPH from a CA reactor.
Doug