I have to wonder why folks suggest EI is complicated, compared to like....what?
1. You do water changes, this prevents anything from building up.
2. You dose based on the volume of the tank, this prevents anything from running out.
If you want to reduce/modify, this is easy as well, dose more/less and watch and adjust.
I took out the mls of liquid A and liquid B and grams of this or that.
It's easier than making chocolate chip cookies, actually boring after you have done it 1-2 weeks......
I dose 2 tsp of KNo3, 4 tsp of GH booster, 1 tsp of KH2P04 to my 180 Gal tank 2-3x a week. I dose a mix of Traces 3-4x a week.
This keeps the NO3 around 10-20ppm with a heavy fish load and lots of fish feeding/food.
If the NO3 goe sup to 30-40ppm, not a big deal because the water change in a couple of days will remove that and bring it back down, but it does tend to target that 10-20ppm. Even with high or moderate light.
I think folks are scared of chemical name and adding raw salts to their tank versus using a name brand liquid which has a tiny a bit of ferts and they enjoy paying 100X more for the water in those bottles?
That's mighty $$$ water.
BTW, EI and the concept is not my idea, I just argue for it. Everyone knows large water changes dilute the nutrients and everyone knows adding a know weight of ferts/salts to a known volume of water will increase the ppm's.
The math is not mine either, infinite series? Been around longer than me.
Arguing for common sense is often a tough road for many folks