Soaker hose in polytunnel/greenhoues beds?

[johnjohn]

Aaargh, so many variables! My hose and timer are Hozelock, the timer works absolutely fine as Alison has said, there is no restriction to the water flow. The hose I'm not so sure about, is it supposed to be covered in beads of water? Mine has maybe a dozen beads of water for every foot of length, seems like that would hardly keep a bed watered even if it was on constantly?
Alison, mine isn't buried as I'm still experimenting with the flow, was planning to bury it eventually, or cover it with a mulch or something. It has two non-porous sections that are buried under the cenral path of the tunnel.
Maybe i should buy the Greenkey hose and compare - that would be my third hose though!

Thanks all for your continued interest in this!

Don't buy the other hose!

I stopped of at the Garden Centre on the way home and opened a Hozelock one up- on the back it states low pressure, these are the pics:

Is this what you have?




Sorry your having such a problem with it!

Bl**dy pictures are the right way up on my pc, sorry, no time to sort it out now (wheres BM?)

[bario1]

Thanks for going to all that effort Johnjohn! Yes that is the exact same product (but mine is 15m), I threw the packaging away. So everything is working fine, I guess the problem is either that they just aren't designed to give out as much water as i expected, or my tank isn't producing enough pressure to drive even a low pressure soaker hose.... or there's an air blockage somewhere. Or there isn't a problem at all and the soil is beautifully moist underneath even though it looks bone dry on top... really ought to check that!

[bario1]

Would fitting a 1/4 turn ball valve to the tank increase the flow? Currently it has a standard plastic water butt tap.

[redser]

Thanks for going to all that effort Johnjohn! Yes that is the exact same product (but mine is 15m), I threw the packaging away. So everything is working fine, I guess the problem is either that they just aren't designed to give out as much water as i expected, or my tank isn't producing enough pressure to drive even a low pressure soaker hose.... or there's an air blockage somewhere. Or there isn't a problem at all and the soil is beautifully moist underneath even though it looks bone dry on top... really ought to check that!

Actually that is how they work. If the hose is on top of the soil, it will be wet immediately where it makes contact. But below the surface it spreads out in a triangle as it sinks down. I think I read somewhere that the spread is 18 inches although that would depend on how much water is flowing i guess. So on top it looks dry (which is good as it cant evaporate away) but below, where it is needed, the soil stays nice and damp.

[Kristen]

The only time I've had a problem is when there have been airlocks in the system at which point it just doesn't work.

I wonder, for a gravity fed system, if it would be worth connecting the "far end" to a bit of plain hose, angled upwards (to same height as top of water butt) so that air can be pushed out of the soaker hose, and up the "chimney", easily?

[Alison]

I wonder, for a gravity fed system, if it would be worth connecting the "far end" to a bit of plain hose, angled upwards (to same height as top of water butt) so that air can be pushed out of the soaker hose, and up the "chimney", easily?

I've wondered that too but never got around to installing what I suppose is basically an air vent. Will try it one day.


Sent from my iPad using Grow Your Own Forum

[bario1]

Wouldn't that seriously reduce the amount of pressure in the loop?

[Alison]

Wouldn't that seriously reduce the amount of pressure in the loop?

No, it's not a closed (pressurised) system as it's open at the water butt end. The head of water you have would simply find it's own level and hopefully bleed the air out.


Sent from my iPad using Grow Your Own Forum

[bario1]

I can't get my head around water pressure - can you tell me though, would a wider outlet from the tank to the timer create better flow and therefore more pressure in the loop?

[Alison]

I can't get my head around water pressure - can you tell me though, would a wider outlet from the tank to the timer create better flow and therefore more pressure in the loop?

Sort of as a wider pipe will reduce the frictional head losses along that section of pipe and therefore more flow can get through BUT, the pressure in a larger diameter pipe is actually less as the flow is less constrained. It's not really about pressures as such in the way we talk about water pressure out the tap, more about flow. This is a very simple gravity system and water will ultimately flow downhill so really all you need to do is ensure that the top water level in your butt is suitably higher than the highest outlet point and that there are no kinks and obstructions to stop the flow. As the level in your butt drops, the flow rate will decrease and you just need to set any timer to whatever length of time us needed to provide sufficient watering. So long as your butt outlet is high enough that you could get a watering can under it then you should be fine.


Sent from my iPad using Grow Your Own Forum

[johnjohn]

I was just wondering bario, could the problem actually be much simpler? Have you tried attaching the soaker to a regular mains pressure tap and flushing it through? I'm wondering if there isn't an internal blockage, perhaps during manufacture?

If you attach it in the first instance with no bung in the end you would expect to see normal flow. Next step would be to set up as per your normal layout and turn on the tap in increments up to a half turn so you don't overload it and see what happens, this is similar to how it should look in use with your barrel.

[bario1]

Unfortunately there is no mains to test it with Johnjohn. I'm pretty sure there is no blockage though, as when i break the join at the far end, water flows through both hoses. Not much water is making it out of the system though, as after a couple of 2 hour soaks, the level in the header tank has only dropped a couple of millimetres.



Sent from my iPhone using Grow Your Own Forum

[Bill HH]

I still say ring hozelock customer service, if nothing else it will be interesting to hear what they say. They might even send you a free new hose.

[bario1]

I might phone them Bill, but I imagine they will just tell me the pressure must be too low... in which case, what's the point of a new hose?
I'm so frustrated with this whole thing now, the system is delivering practically no water. It's time to start drilling holes in the hose, I'm going on holiday for 10 days in a couple of weeks and I need this to work in some shape or form! What do people think is the best method, a drill with the smallest available bit, or hot needle?

[Bigmallly]

This may or may not help you bario but yesterday I ran a 15 foot length of hosepipe from the top of my water butt (overflow) into the poly, poked a load of holes in it with a tiny screwdriver & it works perfectly. I could have attached it to the tap but just wanted it as a back up when it rains.