See here:

Want more accuracy? Want daily PMDD style EI dosing?

What is it that you hope to gain by more accuracy?

Plants, tanks etc are variable, species type, biomass etc...........the dosing you do will never be one size fits all via more accurate results.

Basically you worry about accuracy in an inaccurate but variable biological world.
Things are not that rigid.
That is a good thing.

You can dose more frequently, to keep narrower ranges, then still do the water changes to prevent deviations from a standard range(which is some arbitrary range you set).

It's not some precise set point nor will it ever be.
That's why I suggest estimative...........especially at high growth rates......

the dosing calculators are plenty, we have one here, nutri calc.

Simple EI Dosing Calculator

Plug in the amounts you want etc and go from there.
If you plan on doing this, you will have to learn more about it.

Regards,
Tom Barr