[Griffo]

I have a spring-fed pond in my garden and want to use it to irrigate my vegetable plot. The pond surface is about 4 - 5 feet below the level of the plot and about 50 feet away. I already have an old (worn) submersible pump, that I use to fill a water butt (for the greenhouse) but it's not powerful enough to operate a sprinkler system.

I was thinking that, if mains pressure is around 1 bar, then a pump that produces 1 - 1.5 bar should be strong enough to work a sprinkler arrangement?

Has anyone any knowledge/suggestions on what I could consider, in terms of a suitable pump and delivery to my 6 raised beds, please?

[Lardman]

I was thinking that, if mains pressure is around 1 bar

Seems a little on the low side - Mines at 4Bar (I have a pressure gauge) and Id turn it up if I could.

I wouldn't think that a pump like that would give you enough sustained pressure for sprinklers.  Have you thought of drip irrigation or soaker hoses ?

[Griffo]

Lardman - thanks for the reply. That's interesting that you find 4 bar too low, I'm sure I've read that mains pressure is 1 bar and that's enough for most sprinklers isn't it?

I don't think drip feed is viable over 6 raised beds (each about 20 feet by 4 feet) really. I would much prefer a good, fine sprinkler to give comprehensive soaking. Haven't really looked at soaker hoses, are they much good?

At present, I have stepped the pipe from my submersible down from 1.5 inches to normal hosepipe, which fits inside a length of plastic pipe with holes drilled in. I then move this around the beds. This is reasonably OK except that the water soaks down and out underneath the retaining boards (flooding the paths), without properly wetting all the soil. This is why I feel a fine sprinkler would do the job better.

[gobs]

Soak pipes and the likes are a much better way of irrigation though.

[Lardman]

My understanding - and Im by no means 'technical' is the 1bar is normal air pressure at sea level and as such no where near enough to run sprinklers.

It's actually a really complex subject, I suspect you may be better starting at the other end. Look at sprinklers and check the spec's they require. Id imagine they want high pressure low flow which isnt really going to fit with a standard pump, it may even burn it out prematurely.

I use a similar system to the one you describe - I buried 1inch waste pipe with holes drilled in either side of my bean trench. I just stick the hose down the vertical and leave the tap on.

If you're flooding the area, you're probably using too much water too fast - try reducing the size of the holes in the plastic pipe, anything over 3/16th is probably too big.

The tech's in design and construction may well be able to help better than I can.

Edit ...

A quick google brought this up. http://www.irrigationtutorials.com/#sprinkler

[Trillium]

I'm with gobs on preferring soaker hoses or drip irrigation. The water goes straight to the plant root area in a slow trickle which is absorbed rather than washed off, and the soaking goes deep where most needed with the least amount of water. Use a timer, about 6-8 hrs of the slow trickle and you're good for a week.
Also, sprinklers wet foliage which causes problems down the line: sunspot scald on leaves if it's a hot sunny day (acts like magnifying glasses), spreads fungus spores, creates a perfect climate for mildew, can spread pests around, etc. It's also very wasteful no matter how you direct it compared to soakers or drip systems. I'm sure your low pump pressure could easily handle this sort of system as its slow.

[Griffo]

Thanks for the replies (and links, Lardman).

I am in agreement about using some form of drip system, having tried various drilled bits of pipe running from my submersible pump. The delivery is too rapid, so drains down and out without thorough soaking.

I'm now thinking of using a water butt for delivery, filling with my pump. One 50 gallon butt full should easily soak each bed (approx 15' x 4'), refilling for each bed. This would also allow me to deliver some liquid feed as/when needed.

Question: (you knew there'd be one) which kit to buy? A lot of sites seem to offer this one  http://www.twowests.co.uk/TwoWestsSite/product/WBDK.htm

Has anyone got experience of this kit or similar, or any alternatives they can recommend please?

[Griffo]

Someone must have tried something like this surely?

[GreenOwl]

Have you tried an actual soaker hose rather than drilling holes in pipe?

I find I haven't got the drop from my water butts to use with it - plus my water butts fill from the roof so in hot weather, once the water's gone its gone.  I use my soaker hose with the mains tap, turned right down - otherwise the plug in the end shoots out and the water comes out the end instead of along the hose.

I can recommend proper porous hose rather than hose with regular interval holes in.  Its not usually cheap but Lidl did some earlier in the year and its just like the stuff I paid 3 times the price for over the Internet.  TwoWests call it "Weeping Garden Hose".

[Griffo]

Thanks for that Greenowl. Do you have any idea how much drop is needed for the porous hose to work please?

[Trillium]

Can't tell you prices, but I picked up all my soaker hoses at year end sales, clearances and at liquidation places for much less than store prices, some for as little as a pound, some at 2-1/2 pounds rather than 7 pounds full store price.

[Griffo]

Nice one Trillium.

I'm no too put off by the prices (a lot cheaper than buying another pump, which is what I was considering!), I just want to know how well they are working for people and if they are satisfactory from a 210 ltr barrel, standing 12" - 18" above ground level?

[gregmcalister]

Just a quick comment on the pressure measurements - 1bar gauge pressure actually equates to 2 bar actual pressure because the gauge is at zero under normal atmospheric pressure (1bar).

There are a couple of ways to boost the pressure available and the most common one is to raise the height of the storage tank. If your plot has a bit of a slope then it makes things easier although it may not be as practical on a flat site.

[GreenOwl]

Thanks for that Greenowl. Do you have any idea how much drop is needed for the porous hose to work please?

I think the leaflet I got with it said 4'.  I had about a foot and that wasn't really enough.  Maybe the two-wests one with the drippers would be better as that said 12"?

Good luck and do let us know what you do and how well it works.