Hello David.
You can use any CO2 regulator that you wish. Most will have a solenoid built into them as well. You can always get a regulator that has a solenoid built into it, then using a Hydros Outlet to tell that when to be on/off. Then, you could use the HYDROS Branded CO2 Solenoid as a redundancy, or as a backup. There are so many uses for the Drive Port CO2 Solenoid, in my case, I use it as a redundancy. It could also be used for a CO2 Scrubber. If you are looking for a CO2 Regulator/Solenoid, and you want the best, the CarbonDoser is your answer. It is a bit pricey, but you pay for quality. I use the Milwaukee, a little bit more affordable and still good quality.
Regards,
Connor Sloan