I only had to refill it once. It helped alot I think. I have big ass heater in the clone box. With out the bubbler the RH stayed about 25%. With it the RH Would have stayed at 100% if I didn't vent it just a bitHoly crap, it worked!!! So you just have a mason jar with water bubbling in your propagation dome? How often are you needing to refill the "res?"