That is the idea. Keep a good level of fertilizer in the tank, enough so you know the plants are not deficient in anything. The EI recipes are just a guide, a place to start. You can make any adjustment you want that suits you.
Another way you could do this:
When you are getting ready to do a water change to remove the uneaten food from the frogs add a small dose of fertilizer to the new water. Then you will be maintaining the EI levels.
Dose the ferts in the AM, and feed the frogs in the PM. That way, when you do the water change (in the PM, right before lights out) the plants have had all day to use the higher level of fertilizers. Plants are not so active at night, and the next morning (when the plants are getting ready to use them) you are adding more ferts.
If you set up a schedule of
Tu-Micros, feed frogs messy food, 20% water change
Th-Micros, feed frogs messy food, 20% water change
Sa-Micros, feed frogs messy food, 20% water change
Su- no ferts, 50% water change
That sounds like a regular schedule to me.