In order to figure out the consumption of elements required, daily measurement is necessary.
Eg, test ur water, do not dose anything, then test water again at the same time the following day, U will know how much elements ur tank has consumed. Then dose according to the instruction, and test the same time next day, see if the parameters stay stably, dose a bit more if lower, a bit less if higher. Repeat testing for a period of time and find out the sweet point. Then setup ur dosing pump accordingly.