Backyard Aquaponics
A place to discuss aquaponics

I think I might use mine to construct a pipeline to Cairns

I'll see if I can come up with some more useful advice by Wednesday

I've got lot's of plans for it all - just haven't put them into place yet (and no putting it there is not one of them).

Perhaps you could fashion them into backyard aquaponics fishing poles.

Maybe you could get someone to sell them for you on commission

I remember seeing that steel geomesh tunnel, Tim..
i couldn`t locate it in my bookmarks,but i know it`s there somewhere

Here`s a few i did find..might be useful to someone.

An old "how to" for a pvc tunnel:

http://www.powen.freeserve.co.uk/Projec ... tunnel.htm

This one is a bit rough and ready but might be useful in an emergency:

http://www.inlandbonsai.com/Articles/po ... tunnel.htm

This one is (imho) by far the best bet for getting the most support from flimsy pvc tube

Ideally it should be scaled down, 42ft with good stability may be a little optimistic:
http://www.alt-eng.com/DomePage/DomePor ... allPVCDome

That big dome looked cool. I wonder how strong it is?

Hi Stuart,
Not very.. it can support it`s own weight and that`s about it but
considering it`s the size of a house that isn`t too bad

The pvc is loaded in compression so the longer the section length the weaker it gets.
If you stand a 6ft length of pvc tube upright and push down on the top it deflects in the middle without a lot of effort.. a 1ft length would be a very different story.

Most pvc tube tunnel designs use full lengths for the hoops as if it were equal to steel tube

One of the magazines I buy had an article in it from a fellow here who made a hot house using wooden pallets, wooden planks, cattle panels (heavier welded wire about 54" tall and 16' long), some 1/4 or 3/8 plywood, poly film, a used storm door, cinder blocks and tie down strapping. Over all it looked doable, but involved a lot of work.

What he did was dig a trench and set the cinder blocks into it. Next he nailed some planks onto the tops and bottoms of the pallets and set it on edge to make a knee wall, then he constructed end framing. He took the cattle panels and arched them from knee wall to knee wall. Then he took 4 to 6 inch wide strips of the plywood and set one piece on top of the panels and one beneath, and then screwed them together. Next he covered the entire thing with the poly film and then used planks along the edge to secure it to the bottoms of the knee walls. He stapled polyfilm to the end framing, and put strips of plywood over the poly and nailed/screwed into the wooden framing to secure the poly. Finally, he used the tie down strapping and earth augers to hold the poly down and keep it from billowing.

Like I said, it looks like he went to a lot of work, and I don't know how long his set up lasted, but it served his purposes. He claimed he could get a 40 degree (Faherenheit) gain in a day just from solar radiation! I don't know what his overnight lose was though, he didn't give that figure in his article.

Kevin

Sounds like it was pretty huge.
Gaining heat is easier than hanging on to it. It mostly depends on the exposed surface area, the insulation value and the temperature difference.
Minimise the exposed surface area and increase the insulation value for best performance.
Add a few thousand gallons of water/gravel into the equation and the heating/cooling costs should be quite reasonable.

Actually, it was only 16 by 24 or 28 if my memory serves me correctly. But he did use a gravel floor in the GH that was about 8 inches deep. I don't believe he made any provisions for heating it though, all solar gain.

Kevin

Hi Kevin,
Around here a 16x24 would be classed as huge, most people seem to use meager 8x6`s..they really struggle to keep `em cool in summer.

20ft dia (320 sqft floor) x 9ft high is as big as i can manage .. a 25ft`er would be nice and believe it or not it`s 30% cheaper to make , but it`s a bit tight in a 27ft wide yard

Hex, we need to see a picture of your backyard so we can help you plan

Hi Jaymie,
My yard is pretty big compared to some around here, it`s 76ft x 27ft and runs uphill, gaining about 3ft of height in the process. The top 30`x 27` is reasonably flat though.

I`ve been side tracked lately with a fun project for a charity organisation.. an all timber geodesic that 8-12 year old kids can put up and take down without any tools.

Now that`s out of the way I really should get my finger out and get cracking before winter arrives (again)

I'd be interested in the plans to the dome Hex. Would you be prepared to post them or PM them?

Hi Rup,
What sort/size would you like to build?

Here`s a pic of the all timber dome 14ft dia x 8ft high.
It all goes together with wingnuts..dead easy for kids.
(faces censored to protect the innocent)