The capital outlay is too high in comparison to low technology.

The energy input is high.

Error and failure prone.

With the high cost involved the profit margin is very low.

The way I see it is that the expenditure is usually ignored in studies because the institution is footing the bill.

Great idea but if you mention Tilapia around here they will lynch you. They are a major environmental problem in our waterways.

That is, of course, only an easily corrected detail which doesn't detract from the soundness of your solution.

Great response P&S. This is something we are looking into in our communtiy with a power sation being fueled from our landfill gasses.

I think this technology is most practical and efficient when hooked up to an inexpensive source of heat (ie waste heat from industrial processes). I have recommended that an aquaponic greenhouse system be installed initially at a pilot scale utilizing waste heat from waste-to-energy systems. Once the water treatment systems are functioning efficiently and the water bacterial populations have stabilized (bacteria being a major component of the process) then scale up in stages to full production. A significant issue is designing the system so that it can be accredited as organic. The key is to consider that the fish production component is directly related to the nutrient requirements of the crop plants. The fish are a biproduct of vegetable production.

Good thoughts. Kicking it off as a pilot makes good sense and making sure your environmental issues are efficient is good. In some areas cooling things down is as important as heating.

As a fresh water aquarium enthusiast I have had as many as nine fish tanks in my house. The water needs changed every week and it makes great plant water. My house plants get huge when I use it.

To grow plants to feed fish to grow plants is a semi closed system. Done correctly the sun keeps adding energy to increase the energy to build a bigger loop.

The dual output of fish and vegetables could be a win win.

Brad

Biggest problem is likely to be getting environmental approval rather than technical or financial.

I went to a lecture where the case was examined of an application for a simple fish farm (aquaculture). After 10 years, the list of authorities who had to give approval had grown from about 3 to 23! (2 of these were "one stop shop" authorities meant to obtain approval from all the others so you didn't have the hassle of dealing with so many. They simply became 2 more to be satisfied). The list of items to be complied with, in addition to the original requirements had grown enormously.

The lecturers final comment was "If you are thinking of aquaculture, don't."

If you further strain the brains(?) of the poor bureaucrats by adding hydroponics as well, who can guess how much harder it would be.

Technically, the idea is excellent. One process feeds the other.

In addition, if you set it up near a power station and use both waste heat and exhaust CO2, you could get quite a substantial boost to both processes.

How you would manage to get environmental approval is another matter.