Rather than trying to specifically isolate individual nutrient issues, it is different for every plant species, it's better to focus on good general care and non limiting nutrients.

Then you are not guessing.

That's fine if someone can hit a good range with their system, but they need to know why it works, not just how, because many other folks can try it and fail.

You need to be able to explain for the most part, why it works so others can replicate the test, methods etc.

I think if you use EI, you can work backwards and assume dosing that much nutrients, you do not need to worry about limiting nutrients.
You are adding everything you need to a level that's non limiting.

This is a pretty safe assumption.

So, you go to lighting.
If you have roughly 0.5 w/liter, then you are most likely in a good range, if you have 2x this amount, that's fine as well.

What is left?

CO2 and current, filtration, routine mainteance, algae eaters etc.

But as far as nutrients, CO2 is the most critical.
Many do quite well without CO2 also.
No water changes.
No dosing.

The trade off?
Growth is reduced 10-20X slower.
so the rates you need to add fertilizer can be met solely from fish waste or perhaps you added soil to the bottom of the substrate.

Non stable CO2 gets many folks into a lot of trouble and then they chase nutrients around thinking they are the cause of all their algae.

Many seem not to be able to test CO2 very well, this issue is hobby wide.
The folks who tend to be good growers also rarely test, they watch their plants and add CO2 more by eye than by a test method.

I suggest using both methods, both the sediment and the water column for getting optimal nutrients and growth.

The ADA aqua soil works really well and it is easy to work with(better than sand + soil etc).

Then you do about 1/2 EI dosing for the KNO3, KH2PO4 and full for the GH booster and the Trace mix.

This works really well.

EI is just a starting point, you can and should tailor the method to your tap and your tank. Eye balling the and simply watching will tell you a lot. If your tank pearling really well after a water change, but rarely for the rest of the week, check the CO2.

Clean filters often, most of these things are common sense but many are way too strict and just take some of the advice and forget the rest.

Regards,
Tom Barr