[[EDIT: the point of this system is to give MUCH more control than commercially available watering or irrigation systems. This gives precise plant-by-plant control and controls water amounts & fertilizer levels separately.]]
When I move into a more permanent apartment, I plan to really fill it
up with plants. I'm thinking there should be an apartment-wide irrigation system, not only to save watering time but also so I can be free to travel without drafting other people into plant-care duty.
We're using these (safe) assumptions:
1) None of my plants need to be watered more than twice a week;
2) All of my plants are okay with getting some amount of water at least once a week; and
3) Of the plants that need fertilizer, they only need one variety of fertilizer.
So there's a 10-gallon-or-so reservoir sitting on boxes on top of the fridge (so it's touching the ceiling). I pour water into the reservoir and it flows into two tanks. Water that flows into the first tank just gets Brita-filtered; water that flows into the second gets Brita-filtered and mixed with fertilizer.
Twice a week (on a simple household timer), two things happen:
1) The second tank is gently stirred by a low-powered, rotating agitator arm (to get the fertilizer nicely mixed in); and then
2) Four narrow gates at the bottom of the reservoir open up, letting water flow from both tanks into four long plastic tubes (two tubes flow from each of the two tanks; the reason for this is below).
The four tubes run all the way around my apartment walls, sloping gradually downward (so the water flows with gravity). These four tubes all have short lengths of secondary tubing that branch off to flow into each plant pot. So each pot has four narrow secondary tubes flowing into it. Each of these secondary tubes has a valve that I've adjusted manually, to give the plant what it needs (from nothing [closed valve], to a few drips, to a lot [open valve]).
The four tubes are:
1) Plain water A;
2) Plain water B;
3) Fertilized water A;
4) Fertilized water B.
A and B in each pair flow from the same tank; the difference is that the A gates open up twice a week and the B gates open up only once a week.
This seems to be the simplest way to cover all my plants -- any amount of water either once or twice a week, plus any ratio of fertilized-to-plain water. I haven't made a functional model of this system yet (I'm still working on living in one place for more than two seconds), so it's just an idea right now. I would love to hear any suggestions and URLs!