You shouldn't do that, especially if your regulator is not a two-stage one, because there's a tank dump effect when using single stage regulators. It's when the pressure in the cylinder gets very low and the regulator simply dumps the rest of the co2 into the reactor at one time. To avoid this, check the pressure gauge often> When it drops down to 800-700 psi you have about a week left of co2. Hope that helps