Backyard Aquaponics
A place to discuss aquaponics

In advance, Please forgive my ignorance I'm new. Since having read a paragraph on aquaponics in a self sufficiency book 2 weeks ago I've had sleepless nights. I have this gut feeling that aquaponics has got to be viable as a small business, and the idea will not leave my head, especially since I now have to think of my 2 year old. I'm now trying to get as much info as possible so I can get a business plan together to give myself a better idea. Meanwhile I would like to set up a small system in my parents conservatory to convince them that it could work.

My father has 4-5 large concrete tanks that were used for stocking marine shellfish for over 30 years that he was going to demolish as he's retired. I thought that maybe I could find some way of setting up an aquaponics system using a least one or two of them for the fish and perhaps use another for floating plants that could be used as fish feed. The lettuce e.t.c would be grown in trays on tiered shelving to save on space as I imagine a greenhouse is highly expensive to build , so the smaller the greenhouse the better, especially if it has to be heated in the winter. I'm supposing that I could even grow the veg on tiered troughs or whatever above the fish tanks to save space and to keep the fish in the dark. Other than that I haven't got much clue on pump systems, piping e.t.c. as yet. I thought I could use a mixture of both omniverous and herbivorous carp that can tolerate cooler waters and setting up a wormery so that I would be more self-sufficient as many of you seem to be doing here.

Does this just sound plain stupid or does someone think it could work, especially since this is in the cooler climes of Scotland? Does anyone have any ideas for fish in cooler climes.

Do concrete tanks always need to be lined for fish? We've managed without for shellfish so far, but unlike aquaponics where fish are kept for months the shellfish wouldn't be in there for long at a time (2-4 weeks at the most), so I wouldn't be able to tell. Is lining purely for leaks or for other reasons? Would the salt that may have leached into the walls over the years be detrimental to the fish or is that just stupid? I've so many questions to ask. Again please excuse my ignorance. This is all new to me.

Thanks

Welcome, V!! Oh boy, lots of questions to answer!!! We don't mind newbies at all. Come with an eagerness to share what you know and learn what you don't. And post pictures. We like pictures.

Many of us live in cooler areas of the planet, and work indoors with artificial lights, greenhouses or sunrooms. In the US, we have folks in Michigan (Great Lakes area), Pennsylvania and New York (northeast US), and Alaska (that big state northwest of Canada).

Some members do use concrete tanks, although I think most of them are sealed. The sealing prevents leaks, and also keeps the concrete from raising the pH. Given that your concrete tanks are well-aged, you may have less of a problem with the pH. The first thing I think I'd try is to fill one of them with water. Check for leaks, of course, but also let the water rest in the tank for a few days and compare the pH in the tank to the pH of water left to rest in a clean plastic bucket. That will give you an idea whether the pH is going to shift because of the concrete. A pH betweeen 7 and 7.5 would be ideal, but most of all, a steady pH is best. Marine tanks run a higher pH, so the fact that they are not already lined doesn't suprise me.

There are also test kits for salt, and assuming that you rinsed out the tank well before you filled it, you could run another test along with the pH test to see if you have salt leaching from the concrete. If you do have salt leaching, I'm betting that it will work its way out in a couple of weeks, and the salty water can be disposed of. Interestingly, many freshwater fish can tolerate some level of salt in their water. Those of us eating plants or fish from our systems also don't want to medicate with odd chemicals, so we often use salt to address disease in our systems. Most plants can handle salt at 2-3 ppt and that will be your more limiting factor. When addressing disease, we might dose the fish at anywhere between 4 ppt and 20 ppt, depending on the fish species and how bad the disease is. Some tilapia can handle seawater.

Duckweed would be a great floating plant to use as fish food (or human food!), and is very prolific and nutritious.

For fish species, the first question is 'what can you get your hands on?' The Aussies have a lot of native species that are suited for tank culture. In the US, most folks are using tilapia, although now we have some folks working with natives, too. For a cool-water tasty fish, try looking into native trout. If you want to sell fish to the ornamental pond trade, fancy goldfish or koi might work. I hear that Asian grass carp are tasty, but they're also illegal over here, so I guess I'll never know. Call around to your local hatcheries and see what they would have available in the Spring. They may be able to make the best recommendations about what they have and what would be best for tank culture.

Take a look at the Members' Systems section for pictures and overviews of the various systems. There's lots of inspiration there. The systems are designed a lot of different ways, and you may see something that particularly inspires you.

Oh, in the Members Systems Section, look at the Small, Medium, and Large systems stickied at the top of that section. In there are quick summaries of each system: 3 pictures and a brief description. For the systems that are really interesting (like mine ) you can read the whole thread if you like.

Thanks Janet.
Thats given me something to think about. I think the tanks used to be sealed with some sort of black paint that mainly wore off to wear and tear. Our water comes from a loch up the hill and is untreated but quite acid, so maybe the bare concrete would be fine to increase the ph. That's a relief.

Are grass carp among other fish illegal in Australia in case someone decides to let them go in the wild and they take over disrupting the natural ecosystems?

I wouldn't know about Australian law , but that is the reason why they are illegal in the US. Same problem with tilapia in our warmer states.

Sorry. I didn't look at your flag. Can't mistake the stars and stripes.

We do reserve the right to lightly tease newbies!

The Aussies are the strong majority here, with the US a weak second. We also have a scattering of folks from the Caribbean, Europe, and Indonesia. (I'm very glad that I can put my mouse over unfamiliar flags to get the country name!) You'll be learning Aussie slang, for sure. Glad to have another Sheila on board!

Hi Vlad, welcome
Big concrete tanks would be fun :drool: they would probably be fairly stable with temperature. In Scotland trout would be a good bet, easy to obtain I would think.
Got to go, take the kids to school and such. I'll think of more later

You are late, got a note?

nuh! such has only just finished

Hi Vlad
I am regularlly in touch with one of the BYAP members from the Institute of Aquaculture at Stirling University who has done a huge amount of work on different systems and being not a HUGE distance from you could be a great help. He is on the members list under the Institute so perhaps you pm the man and link up. If you have trouble making contact get back to me and I will sort something out.
Just a thought
WD.