I have switched from a DIY yeast C02 system to a pressurized system and all
is going well. At this point I am just running the Co2 into an Eheim
diffuser 24 hours a day. I am considering going the Controller/solenoid
route ..... just considering it at this point as the 24 hr a day method does
seem to be working out.... and have the following questions:

1) How long can I expect my 5 lb CO2 cylinder to last at a rate of about 1
bubble/sec, 24 hrs/day.

2) What are people's favorite brands/sources for controllers.

3) Is there an inexpensive but reliable controller out there that I should
consider?

4) Are the solenoids reliable, or are they failure prone?

5) How much of a hassle is controller calibration, and how often do you
have to do it? Are some easier to calibrate/maintain than others?