Quote Originally Posted by JaySin
The only problem with that is that if I am almost out of water I will run the risk of frying my pump. Even at the lowest possible water leve,l I have four five gallon buckets that need to be full along with probably 2 to 4 gallons of water that need to be covering the pump. Is this what you mean by being almost out of water? What if I just keep filling it with plain water so the water level stays up but the ppm continues to drop?
I'm pretty medicated right now, but I wanted to answer ASAP, so bear with me. If you want to add a base minimum of water that you never want to run out of, then simply ADD a fraction of the recipe to compensate for the extra water, so the PPM remain the same and your loss ratio of nutes emptied to the garbage at the end of the week will only be that small factor.

Got it? So lets say your girls drink 14 gallons in a week and you run an 17 gallon res, you would put enough nutes for 17 gallons / 7 and at the end of the week throw away 3 gallons of water and 3/7 gallon value of nutes, no big deal.