Irrigation with Idratek

[Paul_B]

Morning all,

As rain seems to be rarer than diamonds at the moment are poeple investigating irrigation systems and using Idratek for control?

I have a 1,000 litre water butt which collects water and I then attach a pump to use the water to wash the car or water the plants. I've started digging a trench to the top of the back garden where my veg patch is going to go. At this point I'll probably have another couple of 200L water butts.

Now for the interesting bit. I'd like to pump from the 1,000L to the 200L and then use a manifold to automatically irrigate the front garden based on zones and data from moisture sensors in the soil. I'd also like to put a tap in the front garden so I don't have use hoses from the back garden. I'm concerned that the pressure will be poor even if I keep the water pipe diameter as large as possible for as song as possible. So in my mind the main factor is going to be the pump and pump control

The pump, as I see it, will need to have the following features:
- Self priming
- Dry run protection
- Filter or dirty water designed
- Startup automatically when pressure drops (i.e tap is opened)
- Also allow control from Cortex based on moisture readings and quantity of water in all butts (manifold valves open, pump starts)
- Low voltage
- Battery operated (as I would think this would be a good use of a small solar panel (long periods of no use to collect energy then short periods of use with relatively low power requirements)

Thoughts, comments, suggestions?

Paul

[toscal]

Here in Spain, this type of pump is quite common as the mains water pressure is either very good or nothing at all depending on where you live. So many houses fit a special pump, which keeps the water at a certain pressure. The pressure is normally factory set and should the water pressure drop, i.e. turning a tap on, the pump will start automatically. Some have a small pressure vessel attached others have this built in and some don't seem to have one at all.
Also you may need to fit a pressure reducing valve to regulate the final pressure.
You could get a cheap standard pump to transfer from the big tank to the small one and have a ball **** or some other form of level indicator that is connected to your Idratek system so when the 200 is empty it will turn the pump on, but only if the 1000 is at least half full.
For filtering normal cartridge based water filters that some people connect to their mains water should do the trick, but they can reduce the water pressure slightly.

Here are some links for you.

http://www.waterpumpshop.com/

http://www.pressurebooster.com/

http://www.pumpexpress.co.uk/acatalog/Water_pressure_boosting_pumps.html

http://www.whalepumps.com/ these are low voltage.

Another method is to fit one of those shower booster pumps I guess Screw Fix or Wickes will have these. But most are only designed for short on durations of about 10 to 20 minutes.

[chris_j_hunter]

we've a broadly similar arrangement in-place, 'though for the moment it's manually operated - it involves around 40m +10m (two legs) of blue pipe, plus 15m ditto in a double run back to the house to allow occasional mains top-up & use of rainwater for flushing loos - we're on a slope, so there's about 3.5m in height-difference between the floors of the tanks at each end ...

some thoughts :

self-priming is common - our Machine Mart pumps are all SP, anyway :

http://www.machinemart.co.uk/shop/range/details/hippo-submersible-water-pumps/path/submersible-pumps-clean-water

http://www.machinemart.co.uk/shop/range/details/electric-submersible-water-pumps/path/submersible-pumps-dirty-water

most have float-valves, which need to move a few degrees from the horizontal in order to switch the pump on or off - which means quite a good depth of water is needed for them to operate (so can't fully empty the tank) ... ie: an alternative sensor & switching arrangement could be a good idea ...

we've found leaves & frogs to be an issue, causing occasional mechanical jamming of the pump & water-inlet blockage ...

when pumps are switched-off, water can run-back, if the levels at each end of the pipe are different ... so check-valves could be good to have ...

pressure-drop could perhaps be due to an empty tank, as well as a tap turned-on ...

dry-run protection would probably be best implemented in a Cortex macro, for reasons of both pump survivability & running costs ...

having both moisture sensors & a rain-guage might be a good idea, for reliability (with consistency logic in Cortex) - the Mini-Click II rain-guage is popular with professionals, so could be a good choice ...

Hozelock offer a number of watering options - including pipe & various forms of outlet, etc, and some pumps & sensors - some of which might be useful ...

[toscal]

Be careful with the rain sensor type. If you live in a humid or very damp area, the sensor can think its either raining or it has recently rained. The expanding disk type tend to have this problem more often than other types.

If the tank is empty there will be no pressure drop as the pressure only gets measured from the pipes coming from the pump to the taps. Basically its tank - pressure booster pump - water tap. I have several clients who have this arrangement in their villas.
One client pumps the water from a natural well to a holding tank, I think its about 500 litres. This pump is controlled from a float switch in the holding tank. There is also a float switch in the well just in case it dries up!!!!. From the holding tank is a pressure booster pump which is used to pressurise the water before it enters the house.

[Paul_B]

Many thanks for the information, gives me some areas for further research