George's CO2 use

Your figures don't surprise me.  You have 90gal=350L.  If you run 15ppm, that
is .015/1000*350*1000=5.5gCO2/tank.  If you figure you need to replenish that
3Xday (gotta be about right), that is 17gCO2/day.  20# = 9000g = 500 days = 15
months pretty close by my figuring.   Do you agree?

Dave Gomberg, Experimenta      San Francisco CA USA   gomberg at wcf_com