"Skunky" wrote in message
...

Having recently set up a pressurized CO2 system, I was wondering roughly
how long the bottle should last. It's a 14lb bottle, I'm using around
30-40 bubbles per minute in a 300 litre tank.

Not sure, but ages! Suggest you weigh the bottle now & then again
periodically to track its use. If you don't have a Ph controller on it its
important that you know where it is - when the bottle gets nearly empty it
can "dump" and stick massive amounts of CO2 into your tank & kill
everything...I'd change it when you reckon there is 1-2lbs of CO2 left in
it.

I have a 7lb bottle on my 90USG tank that's keeping the CO2 at 15-20ppm &
that's been on there since about November....my guess is you should get
12-18 months out of it at least.

rgds

I