only thing about the lucas formular is to be aware that during the plants life, let's say week A, the plant might gobble up all off everything but K or whatever it may be, but as such, your ppm/ec will still read a good number, so when youtop it up, you are just adding more of K or whatever it may be, that it already had enough of and surplus. it works fine, you've just got to keep your eye out and be prepared to refill from fresh. salt buildups and such inside the tote might also want cleaning out periodically.