Review on Optimized CO2 Regulator for 120V Controllers & Timers by Titan Controls by Andy Tunes

Despite what the instructions say, use Teflon (plumber's) tape if you don't want leaks. You should also use a wrench to tighten the bolt 1/2-1 turn after hand tightening. If you installed the flow meter correctly, the tank should not be leaking or empty until the solenoid valve is connected and the main tank valve and smaller knob are turned counterclockwise. CO2 pours in fairly quickly; Don't hold the smaller knob more than one turn until the flow meter reads 2 (I don't know the units). Get a CO2 detector! Aim for 1400ppm in your grow room. CO2 seeps into your living spaces when your grow space is indoors. Turn off the aquarium by mid-evening or use a timer. Levels above 2000ppm will be noticeable to your brain and your plants won't like it either. Lethal CO2 potentially at 5000ppm. Get a CO2 detector! Unless your 20 lb tank is nearly empty, you don't need a flow meter reading greater than 5, even if you vent to the outside. There's a lot of plastic in there. Just hold on to the brass parts or you'll likely break something.