Can't think how to make this work (automatic watering of raised beds in poly)

[gardening_gal]

Thanks again everyone.

After reading your posts, I've decided to buy some 4"x4" for the (6) legs and use what 4"x2" I have for the framing and the top.

I'm going to get some stainless steel coach screws to fasten it all together, those should be much stronger than normal screws I think.

I've also re-assessed things and now plan to make the platform a little higher. I'm going to join both butt taps to the one pipe and feed this one pipe into the tunnel where it will be fixed to a (shortish) stand pipe tap. I wasn't sure if I could join both butt taps together until I saw Bill's pic (thanks Bill!) but it's obviously do-able.

I realised it would be a proper pain to try to turn the water on and off manually if I was inside the tunnel and the taps were outside at the back so I now want a tap inside.

If for whatever reason this doesn't work well, I will use this standpipe tap to join to the main outdoor tap that's around 10m away and go back to just using the butts for a gravity timer type set up.

Sounds a bit convoluted but I can see it in my mind.

I'll post pics when I finally get going. And at this rate it'll be Christmas before the planning stops and the action starts.

[Bill HH]

If you join the tanks at the bottom the levels will even out, if you join them at the top one will fill then overflow into the other. Are you filling them from the mains? or captured rain? If its the mains you could fit a ball valve to one of them and never have to fill it again, in fact you would only need one tank then.

The coach screws sound good but even stronger are coach bolts (with nuts and washers).

[gardening_gal]

These will be rain filled. They wont be near any guttering or the like so I'll probably have to leave the lids off and just cover the top with small square mesh or netting to keep the rubbish out.

I want to join them at the taps so the levels stay even.

I've just ordered some coach bolts as well now. You're costing me a fortune.

(I do appreciate the help. )

[Bill HH]

So how is the rain getting to your water butts?

[gardening_gal]

Is this a trick question?

It's going to come down from the sky and jump into the large round opening at the top of each butt.

Ok, what am I doing wrong?

[Kristen]

It's going to come down from the sky and jump into the large round opening at the top of each butt.

Ah ... I see where Bill is coming from.

You'll get around 2" of rain a month (depends where you are in the country of course) - to fill the Butt you need to collect from a larger area (like a roof). otherwise all you will have is 2" per month. Over winter you won't take any out, so you might have a full-ish butt in the spring, but 100L is only good for one watering, and you'll need a couple a week in a dry spell.

[gardening_gal]

Oh. I get it now.

Makes perfect sense when you think about it.

I'm not sure I can do much about this though, the butts will be behind the polytunnel and not near anything else.

And because they will be on a raised platform, I can't even rig something up to collect from the tunnel roof.

Looks like I might need to re-assess my rainwater v's mains water plans then.

[Bill HH]

Oh. I get it now.

Makes perfect sense when you think about it.

I'm not sure I can do much about this though, the butts will be behind the polytunnel and not near anything else.

And because they will be on a raised platform, I can't even rig something up to collect from the tunnel roof.

Looks like I might need to re-assess my rainwater v's mains water plans then.

AH yes well it comes out a hell of a lot faster than it goes in I'm afraid. You could still fill a seperate butt from the poly rooof and bucket it into you tanks however. My Butts collect the water off a very large house roof and I know it still wont be enough. Is there mains available on site? If you use that you dont really need any butts. Only other thing I can think of involves even more expense like building flat roof which drains into the butts, If it had a poly carb roof you would have another green house! All rather dissapointing for you Im afraid. Maybe just use your system while there is rain water in the butts then swing over to mains water when there is not. If you have electricity available you could pump any water you harvest off the polly up into your butts.

[RedThorn]

You can fit guttering to a poly tunnel too

[RedThorn]

Another idea is fit a butt to the house gutter and connect the two together at bottom as planned. This idea is on the assumption your water butts are same height off ground and the ground is level. Instead of a short pipe connecting them, it'll be a long pipe

[gardening_gal]

Is there mains available on site?

Yes there is but a) it's the other side of the garden across the parking area and b) I was hoping to use fresh water for the plants rather than treated water.

That said, any water is better than no water at all so I'm obviously going to have to compromise somewhere.

Will have to give all this more consideration methinks.

Thanks for pointing this out, never even occurred to me tbh.

[gardening_gal]

Another idea is fit a butt to the house gutter and connect the two together at bottom as planned. This idea is on the assumption your water butts are same height off ground and the ground is level. Instead of a short pipe connecting them, it'll be a long pipe

The distance and siting of the butts make this not really viable unfortunately.

[Alison]

I harvest loads of water off my polytunnel roof as shown below, I don't find that any additional height is needed on the water butts other than the basic plastic stands that came with them.

[RedThorn]

The trick is all the butt's at the same height, otherwise the lowest one would overflow potentially ....

[Bill HH]

I am interested in how you are set up, I presume this isnt an allotment but a private house? If so how far from the house is the poly? does the ground slope up to the poly or down? How big is the poly?