- Drill [or anything that makes nice, small holes]
- Hot Glue Gun ['or waterproof glue']
- Aquarium Tubing [drinking straws work too]
- Water Bottle
Step 1: Diagram
Imagine this picture without the "air in" tube, and you have yourself a basic waterer.
The problem with that setup is that air cannot get into the bottle without having to push its way through the water hose. That's why you get that gurgling sound when you empty a water bottle too fast.
The addition of an air tube allows the water to come out quite quickly.
Note that the air tube extends all the way to the bottom of the bottle. When you tip the water toward the bottle cap, the pocket of air moves to the back, and it can escape only through the tube.
By placing an air tube in the cap, you make it universal. You can screw the cap on any bottle that fits and begin using it as a waterer!
(Caution: clean the sugar water out of your bottle before watering. Plants don't like Gatorade)
Step 2: Construction
I used aquarium tubing from Walmart. It costs about $4, but you get a lot. I've been using the same couple feet of tubing for months. I don't see any reason you couldn't use drinking straws, though. Even two Bic pens with the innards removed would probably work fine.
Work the tubing into the holes and seal the edges with something. I find that Hot Glue works great at making things air-tight. It may not last forever, but it sets up in seconds. (I'm very impatient).
I chose not to have my air inlet flush with the top of the bottle cap. That just gives the glue a few millimeters more to hold onto.
Make sure your air inlet hose makes it all the way to the bottom, or is at least touching the side of the bottle. If it terminates in the very center of the bottle, it's not going to work when the bottle is full of liquid.
Your outlet hose can be as long or short as you want. Some of my plants are very hard to reach, so I've kept mine quite long.
Note: If you're watering and only have one hand free, you can use your finger to block the air valve when your plants have had enough. In a few seconds water should stop flowing. Neat, huh?
Tell me about your plant watering system, or modifications you can think of for this design.