OK, I am back and have re read some stuff and considered how best to help. Here is the thing, in the Lucas formula he has threw trial and error been able to formulate an add back system that works for the 3 part schedule and to try the same add method with other products may just be counter productive. Over all when you use or study his formula, if you can do it according to how he says then it is less maintence then many other nutes and feeding schedules that do not correspond with MJ though many will disagree. Here is why IMO, he has it sorted out so that you can do the add backs in such a way that you may be able to go threw an entire grow with only 1 to 3 res changes depending on veg time really. If you do the first add back method, Just adding a topped off amount of PH'd water until you have topped off with equal amount of the res size, example you have a 23 gallon res you could topp off 23 gallon worth of times and just calculate needed PPM requirements and you could get about 3 weeks or more out of one res before a needed change, and then you could just do a change and flush for 12-12 then I would go with topping off with full strength nutes until the PPM arose above the acceptable level. There is the possibility of excess amounts of certain nutes being left in the water, but if you understand your strain you will quickly notice and this formula has been used so many times by so many growers that any little variables have not been enough to disqualify the formula from being the most popular out there.
Have more to say, but my attention span is wavering right now sorry.
Adieu