Soaker hose in polytunnel/greenhoues beds?

[bario1]

Hi,

I'm thinking of putting a soaker hose under the soil surface in my polytunnel beds. Has anyone else done this, and would it be possible to feed them from a rainwater butt rather than mains water? How long would they have to be left on each day to provide sufficient water on an average summer day? Sorry if these questions seem vague, i'm just toying with the idea and want to know if it would be worth my while?

Thanks.

[roitelet]

I would have thought that a soaker hose could well empty a water but if there isn't any rain to fill it. I use soaker pots and somewhere there is a thread on here with pictures. They only need to be filled every 4 days or so and economise on water and labour lugging watering cans. I have used them for several years and find them really efective.

[Aberdeenplotter]

I leave my soak hoses on top of the soil and cover with black and white polythene, white side up. Yes it will work from a water butt.

[bario1]

Thanks Roielet, I'll look into soaker pots... but i still like the idea of a hose, i think the Heath-Robinson aspect of the system appeals to me. The water butt would have a tap at the bottom which the hose would be attached to, so it could be turned on or off, rather than draining the butt completely. I'm just wondering how long it would need to be on for to give the bed sufficient water for the plants above? How slowly does the hose 'leak'?

[roitelet]

It's soaker pots that are Heath Robinson!

[Kristen]

I'm just wondering how long it would need to be on for to give the bed sufficient water for the plants above? How slowly does the hose 'leak'

Probably best to work on the basis of Litres per Plant, rather than time for your calculations? And that depends on the size of the plants a bit - Lettuce will need less than, say, mature Tomato plants - although the Lettuce will be planted closer together. Can't exactly remember but I think I give my Tomatoes (planted in the ground, in the greenhouse) about 2L of water each, once every 3 days or so.

The water butt would have a tap at the bottom which the hose would be attached to, so it could be turned on or off, rather than draining the butt completely. ?

When the water butt is low you might be waiting a while?

There are battery operated timers you can get. Beware that some need mains pressure to be able to turn off (no, I have no idea why significant water pressure is required for them to turn off! I would have thought less pressure would have made the job easier, but perhaps they use the water pressure to assist in closing the valve?) Anyways, you would need one that can turn off at low pressure. And a decent filter otherwise things will get bunged up with the detritus coming off the roof into the butt.

[redser]

Thanks Roielet, I'll look into soaker pots... but i still like the idea of a hose, i think the Heath-Robinson aspect of the system appeals to me. The water butt would have a tap at the bottom which the hose would be attached to, so it could be turned on or off, rather than draining the butt completely. I'm just wondering how long it would need to be on for to give the bed sufficient water for the plants above? How slowly does the hose 'leak'?

Only trial and error will tell you. It depends on a few factors. How big is your reservoir? How full is your reservoir? How high is it off the ground, headspace? How long is your hose?
I use them in my tunnel and it works great. But I use a 1000 lt IBC tank which is raised 1 meter off the ground so I get nice pressure.

[Aberdeenplotter]

I use a blue barrel 15" off the ground and that works fine too

[Alison]

That's exactly what I do - there are quite a few threads about this already, there's probably more but there's a few below, a couple of them have photos from my plot:

http://www.growfruitandveg.co.uk/gra...er-hose-2.html

http://www.growfruitandveg.co.uk/gra...nel_71003.html

http://www.growfruitandveg.co.uk/gra...nel_49348.html

http://www.growfruitandveg.co.uk/gra...ing_63565.html

[bario1]

I use a 1000 lt IBC tank which is raised 1 meter off the ground

I think you could fit my polytunnel inside your water tank, redser! The tunnel is tiny, so i can only get a 50 lt barrel 12" off the ground in the corner, but the hoses will be short (4m), and they will run slightly downhill, whch might help.

[Kristen]

I can only get a 50 lt barrel 12" off the ground in the corner

50 lt is only going to be about a week's water I think? Perhaps you are able to refill it with a hose though.

I expect that redser's IBC is outside?

[bario1]

The 50 lt barrel inside will be linked to another one outside (at the bottom), so the reservoir will be 100 lt, but the pressure will only be from the 50 lt barrel. There are 'micro' soaker hoses available that are 4mm rather than 13mm - might make the pressure higher and the reservoir last longer, but would it provide sufficient water? I think they're meant for hanging baskets and pots etc.
I really just want a system that will provide enough water to stop the beds totally drying out if i can't get to the plot for a few days - i'm not expecting to never have to water again...

[Kristen]

Would the 4mm actually need more pressure to operate than the 13mm? (More friction for the water moving through the pipe) Particularly comparing the rate of delivery near to the feed with the furthest point.

I guess you are hoping to just turn the tap on, when you are away for a day or two, but I wonder if a larger bore pipe on a timer would be more surefire.

[bario1]

Maybe you're right, Kristen, now i think about it - i just assumed a smaller hose would need less pressure, but it's been a while since i did physics at school... must look up Boyle's law(?) and work it out! Or not. I think you're right though, a timer would be the way to go, but that's another £30 at least on top of the hose... hmmm.

[Kristen]

Instead of a timer could you have something that "delivered" the water? For example a dripping tap that filled a bucket that tipped when it was full. (Rather like a Japanese Deer Scarer)

A siphon might do - have an inverted pipe in a container that exits through the bottom, once the container becomes full (to a point above the inverted pipe) it would siphon out. Arrange a "drip" into the container which takes X hours to fill it, and then each time it fills that can then flow into the leak hose.

Probably going to cost you £30 in bits, unless you can scrounge them or have them lying around