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Any irrigation system with a conventional irrigation controller can be upgraded to an unpowered system where each solenoid valve is replaced by an Unpowered Wicking Irrigation Controller with 25mm valve. The conventional irrigation controller and the associated wiring become redundant.


This amazing invention lets you set the volume of water discharged by each dripper or sprinkler during the irrigation event. The dripper or sprinkler discharge is independent of the water supply pressure.


The Unpowered Wicking Irrigation Controller uses onsite weather conditions to control irrigation scheduling rather than the static timer intervals in conventional devices.


After irrigation and as water evaporates from the soil, water also evaporates from the container. The water in the container eventually reaches a low level corresponding to the soil drying out. The valve opens and irrigation begins. A dripper attached to the irrigation system refills the container during the irrigation. When the water in the container reaches a high level corresponding to the required watering of the plants, the valve shuts off and the cycle restarts.


Once correctly calibrated, the Unpowered Wicking Irrigation Controller only sends water when plants need it and does not overwater. It responds to the same local weather conditions as the soil. Deep or shallow watering, frequent or delayed watering – all can be accommodated. You don’t have to ‘turn it off’ over winter as rain and cooler temperatures keep the container from drying out. You can leave your irrigation system unattended for months on end.


A polyester cloth wicks water from inside the container to outside the container to evaporate and so the cloth is always wet.


The 25mm valve has flow control so that the flow can be adjusted to suit the pressure limitations of the irrigation system. For example, if you prefer not to use hose clamps on barbed fittings, you can use the flow control to reduce the pressure accordingly.



  • Unpowered (no batteries, no wires, no solar panels, no electronics, no computers)
  • If you upgrade to the Unpowered Wicking Irrigation Controller, the conventional irrigation controller, the associated wiring and the solenoid valve become redundant
  • Use with PC (pressure compensating) drippers or NPC (non pressure compensating) drippers
  • 25 mm inlet and outlet
  • Operating pressure range 70 – 1034 kPa
  • Set the dripper discharge to any value between 200 mL and 2 L by adjusting the float
  • The dripper or sprinkler discharge is independent of the water supply pressure
  • Adjust the interval between irrigation events by adjusting the exposed surface area of the polyester cloth
  • Responds automatically to onsite evaporation and rainfall
  • The irrigation frequency increases significantly during a heat wave
  • When it rains, water enters the container and delays the start of the next irrigation event
  • Water in the container is protected from debris, algae, mosquitoes and thirsty animals
  • Simple, unpowered, and low tech, and therefore fewer things can go wrong
  • Leave your irrigation application unattended for months on end

Unpowered Wicking Irrigation Controller with 25mm Valve

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