Newly Registered
Posts: 1
Joined: Sat May 01, 2010 6:55 am
Location: Antrim

Automatic Watering


I would like an automatic irrigation system for watering my greenhouse plants, I have a suitable sized water butt which will be at a good height (I need to sort out a filter for the rainwater collection).

I would like something based on a toilet cistern type of system, for example once a day (autmatically) the cistern handle would be pressed and a controlled amount of water would be released into (anotrher water container and then into) some form of micro irrigation system, one tube to each plant - delivering the same amount of water to each plant, then the cistern would fill up ready for the next days watering.

I don't like the idea of drippers as they could all to easily clog up.

I am going away for a month and want to ensure that my plants can get watered - and I beleive it would also be a good way to ensure that each plant gets the same amount of water each day when I am around as well.

Any thoughts?

Super Green Thumb
Posts: 2179
Joined: Thu Jun 25, 2009 6:06 pm
Location: North Texas

I would simply use a battery powered timer on a common pipe from the cistern you want to use. Set the amount of time and frequency you want it to open and it will do the job for years with a single battery change out each year. They cost less than $30.00 at Walmart and Home Depot.

I'm not to sure about the gravity feed system. The success of the system depends entirely on the elevation of the cistern above the plants to be watered (this is called the head measured in ft.). The elevation must be high enough to produce enough head or pressure to force the water into and through the piping. The longer and smaller the tubing and the lower the head, equals lower flow. Plants closer to the water source get more water. Plants farther from the source get less water. A simple pond aeration pump with a relay between the timer and the pump to turn the pump on would give you a pressurized system. You could also use a negative pressure initiated relay in the line between the timer and the pump to start the pump. When the timer opens to allow flow, the pressure drop between the pump and timer would start the pump. When the timer closes the flow, the positive pressure would shut down the pump. It would be similar to the on/off system used by folks who have their own submersible water wells. You maintain pressure in a pressure vessel with a pressure activated relay which turns your well pump on and off. You will need a relief valve in the system between the pump and the timer. When the timer closes, you will have a pressure surge which could damage the pump or the piping or the timer. A relief valve can be set to the pressure you desire and then pipe it back to the tank or cistern.


Full Member
Posts: 47
Joined: Wed Feb 18, 2009 2:30 pm
Location: Mokelumne Hill, CA

If you do not want a pressured system such as drip irrigation, an alternative would be a capillary system.

Thick nylon rope in a hose or tube of some type can be used as a water whick.

Bad thing about this type of watering is the general requirement of engineering the whole thing ahead of time. Hard to build for established plants.

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