how long will a 10lb co2 bottle last?

atleast 6 months
 
I have a 5lb CO2 tank and it lasts close to 3 mos. so I guess a 10lb one should be around 6 mos. I wanted to use 10lb tanks but the closest exchange place for me only had 5lb tanks available for quick exchange. You gotta be careful and tighten your regulator nut really well. The last tank I switched out only lasted 2 wks cause I didn't tighten the nut enough. Some people suggest that you make up a bottle of soapy water and spray it on the connection to see if it leaks. If you use a washer, you have to use a new one each time you change out your tank/remove the regulator to keep it from leaking. I ended up using a perma-seal even though I still have a bunch of washers left.
 
the soapy water works like a charm...although i dont have a planted tank use CO2 I use many cylinders at work...acetylene, argon, MAPP, propane, nitrogren...ect.
 
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