Backyard Aquaponics
A place to discuss aquaponics

Greetings friends

As mentioned in the introduction I have progressed further than I should have. I will therefore show you slowly what I have done. Tread softly on my efforts.

It started with M (11 years) who wanted a vegetable garden. Tricky - knowing myself and dirt. Without belabouring the point, we compromised on geek farming. Aquaponics was tabled as the preferred solution (satisfying new requirements and long time dreams). We started off defining the design requirements we should conform to. These are:
a) All design elements must be inspired and properly engineered.
b) Presentation aesthetically pleasing (we live in a suburb, not on a farm).
c) It must be technically challenging.
d) System must be reliable and require low skilled knowledge to operate (automated).
e) The design goal for the system is to be off-grid.
f) Humane & sustainable treatment of fish.
g) Process must be documented.
h) Consideration needs to be given during implementation of scalability.
i) Work with nature in preference to system optimization/capital gain.
j) Grow edible fish and vegetables (sustainable and organic).
k) Enjoy the ride.

Witin this scope we defined our constraints. These are:
a) Limited sun in garden which limits placement of system.
b) Winter rainfall area.
c) Temperatures go below 10ºC in winter.
d) Area could be water logged/soggy in winter.
e) Wind is criminal. Very high gusts.

Here we go!

The site for an installation was the subject of grave consideration. We have a lot of trees in the suburb and the prime living area is north facing (South Africa is in the southern hemisphere). A position to the south side has been defined. Not optimal. It provides about 4h direct sunlight between the house, boundary wall and trees. It will have to do.
.
The stop sign is the result of dispute with tilers. Maybe it is symbolic.

Since I like to be in control it was quickly decided to house the system in a tunnel. Of the many documented reasons why I understand some and some not. What I do like about a tunnel is the fact that it is protected and allows me to adjust a myriad of parameters which otherwise is left to nature. I can also visualise myself reading a book in the garden while the rain pours gently on the plastic outside.

Size is my next decision. According to A (my better half) there is nothing wrong with a 1 x 2m tunnel with a simple barrel ponics implementation. I have read enough to understand everyone migrate to a bigger system once under the influence. I hate wasting time so motivated for 6 x 9 which fits nicely into the area. Doing a costing of hobby tunnels made me ask myself a couple of pointed questions. IMHO commercial tunnels are mostly un-inspired designed and from a non-expert opinion not that sturdy. I went searching. I found a visionary architect in France - http://www.equilatere.net/ who defined LOBEL frames. His work and ideas had the right elements. After many a night looking at the options I concluded on a design. I dusted off my "strength of materials" studies and finalised a tunnel design which will work for me. Lots of risk - not afraid. I placed the order for the steel. It arrived. This is how half a tunnel looks like:


After basic construction it looks like this:

The following needs to be noted. The complete tunnel is constructed out of equilateral segments (1.8m x 19mm diameter x 1.6mm wall thickness). The ends are flattened, drilled 10mm and fastened with 8mm bolts. The points touching the ground is affixed to a 500mm metal pole concreted into the ground. The open half triangles was later filled in with non-standard segments and held in place by supports for the grow beds.

If you want I will post more photos later. In line with the bigger is better concept I extended the tunnel by another 3m. I will not belabour the effort it took to align the tunnel, nor how you can bend a segment with a ratchet strap, the problems a pipe water level can give your, nor how your cheek bleed if a segment falls onto it. What I do know is - the structure talks to you.

This is enough now for a first post.

is it a kit or did you make it your self?

Good morning Simo
I built it myself. Segments of 19mm diameter x 1.6mm wall thickness pip (galvanized). The ends pressed flat and drilled 10mm. The flat parts had to be bent slightly depending on the position in the tunnel structure. If it is not perfect the 8mm bolts will do the rest. After a while it becomes not that difficult. The trick is to start right.
Neels

On with the story.

The structure is very floppy once you start to assemble. What worked was to select a point (in my case the most southern point), concrete that in place and then align/level all other referenced to this. Here is a corner showing the anchor.


A major modification I made was to separate the ends from the main tunnel. These are connected with a short link piece. The idea here is when covering the tunnel, the main structure is separate and the plastic could be secured with clamps around the complete periphery. Another shot:

(I know the link piece is not painted or galvanized)

The non-standard triangles were then added and supported with a wooden pole for the grow beds - concreted in place. See below:


Once everything is secured to the anchors it is incredible how strong and stiff the structure becomes. You can literally use it as a jungle gym. I have not covered the tunnel at this stage. Because of the "interesting" shape I am approaching this with trepidation. There is going to be a lot of challenges. It needs to look good.

Lessons learned
a) Work accurate - 5mm is not good enough
b) Fix one point and reference all other according to this one point.
c) There must be no air bubbles in the pipe water level.
d) You can compress a steel pipe until it buckles.

Fascinating!
More pix please...
Oh and welcome to the madness - glad to see more Kaapenaars on board

Very clever and very cool, you were really thinking out side of the box or cube or tunnel or pyramid or what ever...

Can't wait to see how you cover it but I love the idea, geometrically (if that even is a word) the triangle is the strongest shape so it will definately be sturdy.

Hey thats very nice, a bit like an extended dome. It sure will be interesting to see how you go covering it...