[MARIMOBALL]

I have a converted fire extinguisher its red but it the same aluminum 5lbs cylinder works perfect. $30 for a used filled 5lbs cylinder you can remove the paint and i will look just like the beverage cylinders I have one powder coated in charcoal color. It has lasted over six months on my 120gal refills are $5-$10. Don't get an extra one you don't need it most places do exchange but I don't advise it because some times the will give you a cylinder with a certified stamp that will expire sooner. Just wait about two days to refill "your" cylinder. Plants will not be affected from a couple of days with no CO2.