You might need some GH booster as well and switch to TMG instead of CMS.

Then you have covered all your bases.

There is no set rule for how frequent or how large the % water changes should be for EI, 50% weekly is just an example.
The math is simple with that routine, no more than 2x the weekly dosing is the theoretical possible build up.

If you increrase the frequency and/or the % changed and the tap/make up water is not adding any, then you will be less than 2x the weekly dosing.

So if you did daily water changes say, 90% and added say 10ppm NO3 after, that dosing would be very very close to 10ppm each day obviously.

What we do is guess the rate of uptake with EI based on the max amount that plants might use in absense of fish etc.

So rather than doing essentially a reference solution every day, we skip a few days and guess the uptake and do not use a test kit.

The trade off is that we have less water changes/work, but we now have variability of about 2x the the dosed amounts rather than perhaps 5-10% variability with daily changes(measured at the same times each day right after the water change/dosing).

Regards,
Tom Barr