Just completed a 3 tier window farm.

Used fishing string to rig up the system, 2 x 3 way valves for the air-lift system, and a lot of tape!

I found that it doesn’t matter if you have the air coming in from equal sides of the tubing or not. In fact, for my system, I connected two air lines together using a 3 way valve, and have that output fixed to a one-way valve. This makes the system a lot simplified. Lastly, have that output tube connect to another 3 way valve. So one side is for air, one side is for water in, and one side is for air+water out.

I also discovered how to use very little air pressure from the air pump to achieve a consistent drip for the air lift. Simply put a one way valve at the reservoir for the water inlet. It works wonders! With the one way valve, there’s no need for the constant topup of water to maintain the water level/pressure for airlift to work. Also, with the valve, I managed to adjust(my airpump is adjustable) the airpump to the minimum power, so it runs close to silent now, and there is NO GURGLING sound at all! Wish I could post a video of this.. I might do it via youtube.

If this project takes off, I’m going to try creating more systems to see how many can a 2-valve airpump actually sustain. My hypothesis is that is can sustain about 5-6 systems, pumping water up to heights of at least 2 metres. My only problem would be the splitting of the air ways to ensure equal pressure.

The seeds have just started to germinate.

=)