Choosing the wrong CO2 tank size can mean frequent refills, higher costs, and interrupted beer service—none of which are good for your business or your enjoyment.Typically, a 5 lb or 10 lb CO2 tank is ideal for most home or small commercial kegerator setups. The perfect size depends on your consumption frequency and space availability. CO2 Tank Size Guide for Kegerators When selecting your CO2 tank, consider these key factors:  Usage Frequency: How often you serve beer. Number of Taps: More taps usually mean more CO2 consumption. Refill Convenience: Larger tanks require less frequent refills but more storage space.