hey stealthganjafarma
i went away for a few days a month or so ago, i built an auto watering doo-hickey for pretty cheap
i did do 1 stupid thing with this, in the pic you can see a powerstrip on the ground...it would have been smarter to make sure NOTHING could get wet, nothing at all should have been on the ground like that, all electrical components should be raised above the water level
here's what i did:
http://smokefrogg-growjournal.blogspot.com/2010/05/ghetto-automatic-watering-may-15-2010.html
supplies:
1 electrical timer that can turn on/off to the minute, hour or 1/2 hour won't be enough ($15 @ osh)
1 small aquarium airpump, i'm using one suitable for 10 gallons or less ($12 @ fish store)
1/4" drip line ($4 / 50' @ osh)
1/4" drip line t connectors, cross connectors, extenders, this is up to you
1 gallon + jug full of you favorite water, leave an inch or so at the top of just air
the idea is this:
1 tube running to your plants is jammed into the water jug plastic so as to be airtight, this tube's opening needs to be touching the bottom of the jug at the maximum water depth.
1 tube running into the top of the jug where there is an inch or so of airspace, this will lead to your aquarium water pump. even though this is super safe, i still would recommend raising the airpump higher than the water jug.
when the airpump is turned on by the timer, air is pumped into the water jug, this creates pressure which slooowly forces the water out of the other hose which drips into your plants!
this will take some playing with to dial in, mine isn't dialed all the way in yet, but so far it seems like i only need my pump on for 2 minutes every day, that actually might be more than enough.
i am not using any emitters on the drip lines, just drip hose ends directly over the dirt where the plant stalk is going in, i figure there is less chance of something clogging up the line this way
here it is:
there is a timer next to the power strip on the right turning the airpump on each day at 8am and off at 8:02am, the airpump is on top of the white box in the bottom of the picture, line going out to top of arrowhead jug pushes air into the jug, a line going out from the left side of the arrowhead jug is going to a splitter, one end of the splitter leads into the flowering cabinet on the upper left of the picture, the other end is going into the white baby veg box that the airpump is sitting on top of, this splits off to the 5 small plants inside
