The problem, part of the garden is across this wash and there is no water or electric available on the other side...But I needed a regular delivery of water to some seedlings.
So.. get out the wallet and engineer.
Trash can with water, 12 volt pump, 1/2 inch drip tubing. Well Az sun is mean.. so after a year have replaced the rotted out trash can with a 50 gallon plastic syrup barrel... in the market for something bigger and as tough as that syrup barrel..
12 volt Timer.
Solar Panel and some of the 1/4 inch drip going to one of the lucky plants.
Here are the links to the parts:
Proven Pumps Model 3BPLA Submergible Pump from Pumpworld. The guy at Pumpworld was very helpful and added a spot of silicone to where the wires come out of the pump to ensure waterproofing. Don't run the pump dry... so do your math twice on trash can capacity vs. number of days between fills vs. number of gallons dripped per day.
Solar panel is Uni-Solar US-21. This has 21 watts output for the southwest, some less sunny place may need more beef. (Of course, if you lived in a less sunny place, the water might come out of the sky and you wouldn't have to do any of this.) Here is a site to assist on aiming the sucker.
Flexcharge USA Programmable 12 Volt Timer. Wow, they said I would have it in 2 days and I did. But watch out.. the Flexcharge guy really takes pride in his timer.. and when you send it back to him with corrosion evident.. he will really let you have it! Yes.. I promise I will never let this thing sit in water ever again sir. Sweet jesus this is Arizona sir.. how could I have known?
FAQ
Q: Why not something simpler like some kind of battery operated valve with gravity feed for the water?
A: I could not find an electric valve which did not require water pressure to operate and there is very little water pressure out of the bottom of a garbage can.There was once such a beast made in the 1980s called the Rainmatic 3000, but the timer in my second hand copy no longer works.
Q: Why not forget a valve or pump, and just do a permanent slow drip?
A: Hard to do with a 44 gallon trash can over 1 week intervals.
Q: What happens when it is cloudy?
A: The plants do not get watered.
Q: Why not add a battery to make it reliable?
A: More money and you also have to add some kind of battery charge control which is more money again. RRRRRRRRRRRR. Project update: had to add the small SunGuard Solar Controller (35bucks) that I obtained from BackWoods Solar, and a 5amph battery (20bucks) that I obtained from Batteries Plus. My assumption about the panel charging the battery that is in the timer was wrong... it just runs out and then the whole mess dies. So far, this update has it all working just peachy.
Q: Why not just get off your rump and carry water up there every day?
A: Not an effective strategy if you are out of town, busy, or lack consistent ambition.
Q: Any surprises during beta test?
A: Yup... syphon. Once you get the water going... it keeps going, even after the pump stops on schedule. So I resorted to voodoo and added an additional length of 1/2 inch tubing in the bottom of the trash can hoping that the supply side of the syphon would exceed the draw side. I also added a manual ball valve in the 1/2 inch line to restrict the water flow some. But ultimately, be sure you are pumping uphill. Sigh.
Nothing to do with the story, just pretty and around while I was taking pictures of the "system"..
