Backyard Aquaponics
A place to discuss aquaponics

Hi, my name is Koos Uys and I am from South Africa. I am living a Bloemfontein in the Free State. It is a wonderful place with hot summers, fabulous autumns and spring, and cold winters where night temperatures regularly drops below 0⁰C. We also have blue blue skies.

Just before I continue, I can for some reason not get my pics to display in the message, even with the tags used.

My interest in aquaponics is quite a long story and it was initially sparked by my concern about the next energy crisis that may be around the corner. One thing led to the other and it was reading for years.

Now I always loved nature, but as a die hard Mechanical Engineer I had absolutely zero interest in the working of biological things earlier in my life and somehow along a line I suddenly understood one day what an enormous miracle all these micro-life and insects are.

With that, our family loves fresh food and the idea to have a good source in the backyard became very appealing.

Finally, after much planning it so happened that I got the time to set up a vegetable tunnel this December and now I simply need to finish the pipe work and things to have my first aquaponics system.


As a quick summary, this is what I have:

1. A 12 x 4.5m vegetable tunnel with maximum roof height of 3.3m. The long side will be motorized roll up sides. This is not finished yet, but our winter is still another 4 months away.

2. 18 horizontal growth beds made from plastic 210 liter drums.

3. I also made provision for a biodigester to handle some waste that is not nice to feed fish or worms. This may prove to be redundant later an the space can be used for something else.

4. I made space to grow potatoes via aeroponics because they can be easily harvested this way.

5. There is space for dedicated worm beds, but I understand that some people put worms directly in the growth beds.

6. In my case, the main product is the veggies and the fish will be secondary.

7. I am not interested in making this commercial, but there is a lot of interest of friends and neighbours who would like to come an buy fresh things from the plants.


A a designer, my style is to design things intentionally to leave open many options. As I am new in this subject and now need to get my head around things to see how it works, what works and what does not, I need to be in a position to make physical changes easily.


Right, in the beginning of December, I was still sold on the idea to grow ALL my plants with root in the air (aeroponics) and although that has some significant advantages, my biggest concern is the fact that one needs an electrical backup should something go wrong. With the roots in the air, the plants will die probably in less than an hour should the water supply be interrupted. Another more difficult thing, is the physical support of the plant.


However, on this site I then read about the method of "Constant Flooding" and it seems to work very well in experiments. Now as far as I understand, "Constant Flooding" is possible as long as the oxygen levels in the water is high enough. That is why plants grows in rivers and the sea.


My thinking therefore was as follows:

I can set up the levels of my my growth beds and the fish pond such that the water level in the growth beds is the same as the top level in the fish pond. (I see it must be about 50mm below the growth bed surface.)

If you look at the first picture in the link below, it should be clear. With the bottoms of the tanks and growth beds connected with pipe work, the water in the system will naturally settle at the same height. This obviously means that my growth beds needs to be perfectly on the same level - but that is simple enough to do.

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

The advantage then is should the power fail, there is always water in the growth beds and at most one needs to put in some oxygen in the water for a few hours which can comfortably be done with a 12V oxygen pump. Then one does not need any power for pumping water. Solar power backup is then feasible and affordable. Because of this more fail safe function, I prefer this method to flood/drain.


Question then: Is there anything I missed in this concept?



And here then a few pics of the tunnel:


https://drive.google.com/file/d/0B-vwbx ... sp=sharing

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

https://drive.google.com/file/d/0B-vwbx ... sp=sharing

G'day Koos and welcome to the forum.

Looks like a good sized system that you're planning!

Those with more time will probably ask you some detailed questions about your intended setup, but I can give the following

- great that your planning to use multiple techniques for producing your desired crops. Many of us do that. Aquaponics is pretty cool, but it's not the ultimate solution to everything.

- constant flood does work well as long as your water contains enough oxygen. You don't necessarily need an air pump for this as there are other ways of achieving a similar result (unless you're heavily stocked with fish).

All the best

Let's put it this way: I think it is the smallest I can go to make the effort worth it.

My fish pond will be about 5000 liters of water and there should be probably another 700 liters in the growth beds.

One of my ideas is to make the tunnel self sufficient in terms of heating requirements and it seems to be quite possible even in winter.


That will works as follows:

I will budget to deliberate swing the water temperature each day within reasonable limits and more water means less swing. That will be done by circulating the water through an ordinary heat exchanger with a fan on it. In summer I will drop the water temperature at night to allow for the raise of the next day.

In winter, I will do it the other way around. Although we have very cold nights, our day temperatures in winter are at worst about 10⁰C (usually it approach the early 20's) and we have full sun, so even in winter veggie tunnels easily runs on 30⁰C. So in winter, I will simply raise the temperature of the water at day and allow for a drop at night. Simple and cheap, no solar panels.

The only expensive thing there will be a programmable controller, but that is my bread and butter so I have more access to these things.

After NUMEROUS setbacks, I FINALLY managed to at least get the water flowing on Friday.

Just to give a bit of an overview of the trouble.

First of all it took nearly 3 weeks for the fish pond to arrive after order, but that is probably to be expected for ordering in the first week of January.

Then my borehole pump seized when I was ready to try filling the pond with water.

I had to get a new borehole pump and in that time another family crisis had to be attended to first.

After the borehole pump was fixed, I started with the pipe work and strange enough found that PVC fittings was suddenly in desperate short supply and I could only get a fraction of what I needed.

Eventually that was finished and when I filled the pool, I found a huge leak due to my own lack of knowledge and that had to be fixed.

But all is good now and I could get the water going.


Fist of all, my plant buckets fills from a 20mm pipe via gravity feed from the pond. On the bottom it drains into a manifold from where I routed the return pipe to an open tank with a plain old 300W sump pump and float switch to feed the water back to the pond.

The grow media is Coco Peat.

I decided to use Coco Peat Chips for the bottom layer to get better drainage there and Fine Coco Peat as a top layer which basically now solved the problem of germinating the seeds. I can now simply plant the seeds and forget about them.

The growth beds works on a continuous flood principle.

My levels was almost perfect and the inflows to the buckets are almost correct, but I will have to tune that a little bit to get it even.

Now for getting the bacteria population established.

Coco peat is not the best media choice. A gravel of some sort is much better. The peat will stain your water brown from the tannins, and water flow is paramount. The peat will not flow fast enough. You will get anoxic zones. When sizing photos to link, make sure they are no wider than 800 pixels.

Pros and cons to everything.

Many people seems to be quite happy with Coco peat. Can't see why the Brown water is a problem.

My system flows about 3000 litres per hour do each bed has the water replaced every 10 minutes or so and I have some plans if I see oxygen is a problem in the beds.

Sent from my GT-I9500 using Tapatalk

Again, make sure your photos are no wider than 800 pixels.

Sorry about the big pics.


But:

1. I Can't see any button to edit my post.

2. It could be a simple setting in the forum software that will automatically shrink larger pics to a maximum size. The other forums I post on does that.

You don't need to edit your post, you need to resize the photo on whatever photo hosting site you are linking to.

Google+ does not have the option AFAIK. I tried that too.

If you are more interested in me re-sizing the pics, then I will just read here and not give any feedback about my experience.

Thanks for the hospitality.

If you re upload photos to the correct size, pm me with the new links. As a moderator, I can edit the posts for you.

Hi koosjr, I use a free program called Fotosizer, very easy to use, then I upload to the forum using the upload attachment button. Hope this helps.

Hairycamel. I simply linked it from Google+ since my phone automatically uploads it to there. It was already in the smallest size that my phone can take pics.

Is use Fotosizer on my Window$ machine too. Works great for batches. Otherwise I use Linux tools.

Perhaps I should just kick Google+ under the butt and sync to Dropbox where I can make changes.

Still: It should be pretty trivial to have the forum software limit the display sizing. I can almost bet it can be done in the backend settings.

And of course the fact the the poster cannot edit his posts makes some work for the mods so it is a multiple number of issues that has effect.

Hi koosjr. Welcome to the forum. I would be careful of your media choice as well. It won't drain fast enough, and has a tendency to stay too wet. Like Ron said, most use a gravel, small rock/hydroton mix. I like the larger rock on the bottom(3/4-1') 70%, then 3 inches of hydroton to plant in. saves on $$, and is a good compromise. Not sure about the pump, but it looks like a sump. Be careful if it contains any oil in the motor. It can cause a massive fish kill. I like your metal fencing rings with liner for your FT. We have used the same idea for large plant containers in the nursery. Just concerned that you may want to bend a few smaller rebar around perimeter for strength?? Your GH looks awesome! Good luck and keep us updated. I have to upload my pics to a separate program and then downsize them to a smaller size before adding them on the forum. Kind of a pain, so I don't post as many pics as a lot of people. What kind of fish will you be raising?

Coachchris,

The sump pump itself does not have a sump with oil, but I have detected a small oily layer on the water when the system was filled initially and I drained most of the first water to flush out what ever residues there was in the system. I will check it out though.

I will make very sure the water quality is stable and fine before I put in fish so I suspect it is still another two or three weeks at least before I commit but I will jsut put in a few gold fish or something for starters.

The Fish Pond is industrial quality so it should work well. Very strong liner and the steel mesh is the main support.

Right now, I am not too concerned about the cocopeat. I am aware that it absorbs a a lot of water so what I did is to simply make the flood line very low. I am now monitoring it and on the hottest part of the day the top layer just starts drying out. It does not get soaked at night and if that is a problem I can start cycling the flow.

Bear in mind that here in South Africa we have very little choice of media. Our local gravel can swing PH quite badly and the hydroponic balls are extremely expensive.

On the tunnel itself I still have some work. I need to put up the roll-up sides now as winter will be here in 2 months and I have some plastic to trim.