CO2 Tank Auto Switcher

[Dennis Cartier]

300 psi

 

[Dennis Cartier]

200 psi

Next update will be the tank cut-over, switching from the main to the backup tank. My gauge only has markings down to 200 psi.

Hmm, I wonder if the cut-over will happen this year or next?

 

[Dennis Cartier]

The cut-over finally occurred. I thought it would be on Sunday, then on Monday, then on Tuesday. When it made it all the way to Wednesday, it was literally running on fumes from the main tank. My CaRx does a purge and replaces the CO2 in it's gas pocket twice a week, with one purge being on Wednesday morning. There was no way there would be enough gas left for that, I thought. Nope it made it through fine and I had to wait until late in the day before it drained the last remnants from the tank, and it finally switched to the backup tank.

The Harris dual stage regulators I use performed great. The psi coming from the regulator only increased by a 1.0 psi while the last bit of the tank was being drained.

So real world test concluded.

 

[Dennis Cartier]

I was awoke this morning to the sound of an alarm going off. I assumed it was a leak detector sounding as I had just last week moved some tropical plants in for the winter and setup automatic watering for them. I added leak detectors that close a ball valve if a leak is detected. After checking the plant area, and my RODI system for leak alarms sounding, I eventually went to the fish room, thinking maybe it was CO2.

I was surprised to find it was the tank switch over alarm sounding. As the backup tank was already being used, all I had to do was flip the switch to silence the alarm. I was surprised, as I had not been following the CO2 level in the main tank, and was not even aware that it was running out.

Checking the gauges, the tank pressure shows 0, and the regulator pressure shows 13 psi. I have the tank switcher set to toggle at 14 psi, so it worked perfectly and drained the in use tank all the way down to 13 psi. Perfect.

I got about 9 months from the 10# tank. This is a lot less than I was getting, but I have switched to a daily auto vent on my CaRx controller, so the CO2 usage is faster as a result. I am dosing 9 ml/min currently on the CaRx.

So the tank switcher worked exactly as hoped. It saved me from an unexpected interruption in CaRx operation, and I did not have to stay on top of it, which clearly I wasn't, lol.