I'm looking on ebay at regulators and since they're so common in hydroponics and brewing theres a lot to choose from. (I even found one for $40 with free shipping, no solenoid)
I don't understand how to tell what sizes the connections are on the regulator, do I need to figure out what it takes for bottle attachments and outlet? are these something easily adapted or changed? (finding adapters can be a total pita in my experience)
what considerations need to be made for a regulator?
Experience is usually required for CO2 regulators. You need to have a CGA320 nut and nipple for the high pressure side. This is standard in North America. Asia and Europe use different standards.
For the output side, it is usually 1/4" female NPT.
From there, it depends on the other parts you have (i.e. the solenoids I use are 1/8" female NPT, so I need to use a reducer from 1/4" down to 1/8", etc). These parts can usually be found at your local hardware store.
Other considerations when choosing a regulator:
Dual stage or single stage?
One gauge or two?
Chrome plated, brass or stainless steel (all work for our purposes; this is more aesthetics)
Maximum delivery pressure?
And of course,