EI is much more of a concept than a specific dosing method. The basics behind it are:
A reasonable excess of any of the basic nutrients does no harm.
If all of the nutrients are available in at least the minimum concentration needed by the plants, the only thing that will be left to limit the plants growth rate is light.
If you do regular big water changes none of the nutrients can build up in the water enough to cause any harm.
You can follow the tables in the write-ups for EI dosing, and know if you do about 50% water changes every week, the highest concentration of any of the nutrients will be limited to twice what you dose between water changes. But, you can also do some experimenting with the dosage amounts and end up with just a little more than needed, so you can stretch the time between water changes to every two weeks or even every month. Or, you can reduce the size of the water changes from 50% down to 25% or maybe even less.
It is up to you to adjust the dosage amounts to fit the needs that you have, but you do need to do the experimenting first.