I agree with CS on this one. I know I was on a budget when purchasing a pressurized system. I opted to not get a controller to save a few dollars. I haven't had to adjust my needle valve in months (since I got it setup). I have soft water so I have to buffer up my KH weekly via sodium bicarbonate. I just make sure I buffer up to the same degree weekly and I have zero problems maintaining the same level. I leave mine on 24/7 as well. I'm sure it wastes more co2 this way, but it's not like refills are very expensive ($7 for a refill). I basically count the bubbles. I'm a musician so I use a four count in the same tempo each time. I've figured out if I keep a bubble on each quarter note I end up with 25-30ppm all day long. Guess it's a weird system but works for me.