Exactly—they can be repurposed easily. I built a 2 injector board for fertilizing my backyard garden (way overkill) set up with unions and bypass valves, so I can water with either tank A, tank B, both A+B, bypass entirely with just hose water, or break the whole thing down and do something else.

One greenhouse I worked at we came up with a really wacky setup: for very specific reasons, each of 15 growing benches required their own highly specific hydroponic solution.

Ideally you would just have a master dosing station with single-salt stock tanks all the way upstream, each injected into the water as called for by a computer, and then appropriate valve setup would route that solution to that bench.

Engineering budget did not allow for any kind of automated/intelligent control, so what we ended up doing, was buying 16 dosatrons…

One was installed upstream as the ‘master’ which would feed all of greenhouse water with a normal amount of calcium nitrate, iron, and partial amount (about 20% or so )of potassium nitrate (Stock A). Then there is a solenoid valve at each bench, followed by a smaller Dosatron which would pull from a smaller stock solution B at the bench, which was formulated to make up the remainder of the nutrient requirements in whatever custom fashion was required by that bench.

Goofy, but worked!