I was thinking the same thing a couple of days ago... Let us know how this works in real live.
So this thing has 15 little compartments that you pre-fill, right?
Only issues I can see are fertilizers getting moist and clogging up the free flow, difficulties in integrating it into a hood, and the price.
For around $20, I set up a powerhead to inject a premixed solution, driven by an electronic timer. Only drawback so far is that the solutions deteriorate somewhat over the course of two to four weeks.
It's amazing how many different ways to dose fertilizers can be found...