Review on Aquarium CO2 Regulator with 12V DC Solenoid - Large Dual Gauge Display, Bubble Counter, Check Valve - Fits Standard US Tanks - Accurate and Easily Adjustable Flow Meter by Brandy Robinson

I refuse to pay more than $150 for a CO2 regulator. I've had it on my 11g with a paintball adapter for almost 3 weeks with no problems. The solenoid works with a timer, turns on and off without any problems. I always hear people complaining about needle valves and I think this valve is pretty accurate given its price range. I may have to lower my rating in the future depending on how long it takes, but for now it's 5 stars. My only downside is that you have to lay the paintball on its side in order for the bubble counter to stand vertically. This problem does not occur with a standard tank.