How big is the Rez on this system? I have a Waterfarm, that the Rez is only 2.5 gallons for the one plant. I need to add water to it about ever two days. So what I did was I drilled a hole in the side of the Rez tank, hooked up a fitting at the bottom of the rez so I could hook a 1/2" tubeing to it, with a valve, and then another section of hose which I connected to another fitting at the bottom of a 5 gallon bucket. I close the valve, empty the Rez. I then fill the 5 gallon bucket with my nuts and water. When I open the valve half of the water from the 5 gallon bucket flows into the Rez. As the plants use the nut water, or it evaporates, more of the water in the 5 gallon bucket flows into the Rez. Walla.. I just doubled my Rez size, plus I can do a Rez change outs with out picking the plant and all it roots out of where it sits.
I did this so that I could leave my plant for a few days with out the PPM shooting to high. But it ended up being good for more then just this.