i believe what earlmarne is saying is that he makes up a super concentrated solution thats pre dissolved into separate parts A and B and then uses that liquid to mix his tanks. i was doing the same thing for a while but now i just measured and kept track of how many scoops go into my res. i pour in X number of scoops, dissolve it for a few minutes and then add X amount of scoops of part B and my EC is always dead on and my ph at 5.8 and i havent looked back since!