Seymour have you thought about running your grows on advanced nutrients ? i no some of their products can be expensive, but there base nutrients arnt they are very reasonable and with the additives you buy exactly what you want depending on your experties and no how. and as you like to play around with n.p.k and talior you resevoirs to exactly what you want them depending on the plants stage of growth, i thought AD would be ideal for you, ive recently been using there sensi grow and bloom A+B as my base nutrients with their voodoo juice, big bud, nirvana, cal/mag and overdrive, and some of my results have surprised myself compared to other nutrients they really do seem to be amazing and the list of their different additives and basses goes on as you probally no!!!!