Depends on the size of your tank and the bubble rate. For my 55 gallon
tank, it would last about 2 months.

--
Bob Alston

bobalston9 AT aol DOT com

"-=Almazick=-" wrote in message
news:QZEcb.429657$Oz4.227690@rwcrnsc54...
If I buy 20 oz CO2 tank, how long will it last?