Polytunnel irrigation, in a loop?

[redser]

Hi. So I was setting up my auto watering in the tunnel yesterday (IBC tank -> timer -> soaker hose). A chap dropped by and kind of being helpful but rude at the same time said, that's no good, you need to make a loop so the pressure will be equal all along the hose. Then he more or less walked away (enveloped in a strange mist) leaving me there scratching my head.
Has anyone got any idea if that is true? I've read that the pressure at the end of a hose would be less than at the top near the tap. But because it is a soaker I was hoping it wouldn't really matter because the water weeps out gently.
Just thought I'd ask before I run out and buy a Y splitter, feeding both ends of the hose on to each spout. Kind of makes sense, I think?
Thanks!

[chris]

Well, on my auto watering system, the pressure at the last dripper is just as great as the first. Mine's a hozelock ac1+ pro I think.

Edit: it's tap fed though, so perhaps that makes the difference?

[Kleftiwallah]

I agree with him and that is just what I've done. With an odd bit of copper pipe I made a 'Y' section. not a 'T' section that would form a slight barrier to supply both ends of the soaker hose as I found the water wasn't reaching all the way.



Thank him for his 'input'. Cheers, Tony.

[redser]

I think a mains tap would make a difference Chris, my tank isn't very high so the pressure is low enough.
Cheers Tony, good to get a second on that. I certainly will thank him, if I ever see him again.

[redser]

Thanks alot for the photo Tony. Nice bit of welding there! Do you just have one big circuit around the tunnel beds, or loops off loops? I see you mulch with plastic. Black underneath, light colour up? Sorry for all the questions but how long are you irrigating for? I have 2 beds (one down each side). Each one is 16 ft x 4 ft. Was thinking 15 mins at 6am and 15 at 6pm.
Appreciate it.

[Graham K]

Definitely a loop, it allows the pressure to stabilise throughout the pipe. Make sure though, that you can still disconnect one end of the pipe so you can flush all the junk out at the end of the season.

[bigchopsbilly]

The height of the reservoir will make a big difference to the pressure and run length that you can use even a foot or two will make a big difference.

also you could at stages gradually decrease the size of the lines being used to boost pressure at the ends.

Gravity fed irrigation

[redser]

Thanks both for the advice. Well I have it set up now and touch wood, it seems to be working just fine. The tank is a foot and a half off the ground and the pressure is good. I'll add more blocks in time as I find them. I have it done in a loop around two beds and like I hoped it weeps nice and evenly at all points. Really glad that guy dropped by that day! It's only 4 days in and I haven't had to manually water anything yet and toms, peppers, cucumbers etc look good. I'm sure I'll tweak it as I go along but it will save me a lot of time at the plot, something I'm very short on

[Urban]

Glad I seen this, thanks I'll do a loop round the greenhouse

[redser]

Just to mention, Aldi and Lidl had garden hose attachments and various watering fixtures recently. I managed to pick up a Y junction/splitter in LIdl, and each spout has a regulator on/off thingy. Its perfect for this, one end of hose in one spout and the other end in the other spout. 5.99.