Quoted By:
Growmen, lend me your ears!
I believe I have devised a fully automatic, evaporation compensated gravity feed rainwater drip irrigation system with no electronics needed.
1) Open top evaporation tank water level will rise or fall depending on rainfall, temperature, and humidity. This serves as the system's on/off switch.
2) Using a float valve placed in the evaporation tank, the flow between the main water storage container and the 'dosing' tank is controlled by atmospheric conditions.
3) As the valve opens, the dosing tank will slowly begin to fill. After filling to the level set by the height of the bell siphon, the dosing tank will distribute water to downstream drip lines as well as a set amount back to the evaporation tank. If the tank fills back to the set point for the float valve, the dosing tank stops being filled. If not, the dosing tank keeps cycling until the float valve closes.
If it rains, the evaporation tank is filled with the same level of rainwater as any exposed garden beds and take longer to cycle again.
During a dry spell, the evaporation tank will drain more rapidly, resulting in more frequent watering. Even during prolonged dry periods, you can still make use of the system with minimal intervention by simply filling the main storage tank.
I struggled to think up a way to use a float valve to replenish the reservoir for some time and finally came up with the idea of using the valve to control the flow to an intermediate tank. Couldn't find anything online about someone else using a similar setup, so I thought I'd share with you beautiful bastards.
