You're using a massive amount more nutrients and water than you need. This is the difference between a properly balanced nutrient profile and one which is not.
To drastically over-simplify it:
When you're given a plate with steak, mashed potatoes, gravy and green beans, anything you don't need or won't eat is left over. Too much beans, and your plate comes back with beans left on it. Not enough of one or more items and though the plate is empty, you're still hungry.
When the mix is balanced and of the correct strength for the needs of the plant, there is no excess or deficiency. The plate comes back clean and the plant is full. While the exact balance varies depending on conditions and strains, a general base formula has been used successfully by growers for decades now. 122-99-171-68 N-P-K-Mg
is what's been tossed around and it's what I've been using for 15+ years.
When this is used with a full pH swing in the root zone, allowing each element a period of full absorption, there is so little left over from errors it doesn't matter. When you add the balanced mix back to replace what the plants have used, it's all in balance. When you use a natural pH swing, without any manual pH adjustments, there is no build up of pH up/down elements from this source.
This is what cleaner cannabis is all about. This is the 20+ year old tech I'm working on teaching more folks about. This is what the common hydro community doesn't understand, and the ignorance the mfg's take advantage of. They sell a hell of a lot more nutes when folks dump their res every two weeks, that's for sure.
Do your own testing (I recommend a smaller personal grow, perhaps?) and reap the rewards for yourself.