Wondering if anyone's played around with a recirculating CO2 reactor design, similar to reef tank calcium reactors. The idea is to use a small pump to recirculate water through a reactor chamber. CO2 and new tank water are introduced on the intake side of the pump. CO2-laden water exits somewhere along the way, often at the top of the reactor chamber. See the many commercial calcium reactor offerings for examples. Bio-balls or some other inert media would replace the aragonite in the planted-tank version. Seems like we could get good CO2 saturation, just not sure about matching the size of the pump to the rate at which new water is introduced into the circuit, or, for that matter, if it would be worth the effort at all.