Backyard Aquaponics
A place to discuss aquaponics

Hi everybody,

I'm Paulo, from France. I've been keeping fish for a few years with the constant trouble of changing the water to keep the parameters right, and using that water in my garden for my veggies. Knowing that this water was full of good nutrients for the plants I started looking into combining the two ecosystems together and this is how I recently discovered that it had a name, and quite a few international addicts!

After having spent hours (if not days) reading numerous threads, I have finally decided to create my own system. It will mainly be inspired from Zsazsa's one given the fact that, here in Europe, we more or less all have the same problem : the climate.

To give you an idea, here is the link toward the climate section of the nearest city (Angers) wikipedia article :http://en.wikipedia.org/wiki/Angers#Climate
At the moment, it's winter time. Temperatures are around 7-8C during the day when it's sunny and not too windy, and drop to around -4C during the night. But last year at the same period, it was very cold (for what we are used to) and temperatures dropped down to -14C during the day and -18C to -20C during the night.

In summer time, we normally have around 32C during the day and 20-25C during the night. But it can go up to 40-43C in extreme summers and down to 20 like we had last year when it nearly rained throughout the whole summer.


So, the idea is to have a passive solar green house, to raise the temperature by about, let's say 5C. That would be the equivalent to Melbourne or Perth's Climate (more or less).

Regarding the fish species, I am a bit concerned. Ideally, I'd have like to have a species that I could raise all year long and that I could also breed, in order to reduce costs (as I wouldn't have to buy fingerling every year or 6 months).

But to have a fish species that tastes nice, grows quickly, and is able to auto-reproduce itself, is not easy to choose.

If I don't heat the water, I can grow native fish such as trouts (in the winter only), wells catfish, perch, pike perch, carp (doesn't have a great reputation in France), largemouth bass, other small fish that are not really edible. Oh, and also some fresh water crayfish, sunfish and an American catfish (Ameiurus melas), but these 3 tend to be invasive and it is illegal to keep them alive.

On the other hand, if I don't take the cost into consideration, I could heat the water and raise tilapia that I could breed or some other huge tropical fish. But this is a costly solution that I would like to avoid.

Could you advise me on the best species to chose, regarding the growth and taste?

For the design, I am currently designing it, but it would be a CHIFT PIST with ebb and flow grow beds and a 1500-2000L fish tank.

Thanks a lot for your feedback.

Hi Paulo and welcome to the forums.

I have a system up and running for two years now even more to the north (Belgium)
Currently this system is located outside and as you may have guessed it freezes over completely in the winter time and I have to shut the system down for about 2-3 months.

My plan is also to build a passive solar greenhouse.

I have been looking in to fish species as well, as for now I'm using goldfish for experimenting (because they are cheap)
But I think when you will build a greenhouse you could consider a perch. (Jade perch or something similar).

I have been looking into the omega perch which is being developed by the university of Louvain and is bred from the Jade Perch. It can cope with water temps between 14 °C and 40 °C, grows fast and doens't require much food and space.

I don't know anything about breeding capabilities though.

Paulo,
If you have option of a basement, or you have option of digging the ground for temperature control in the middle of your green house, then also if you can insulate your green house, and use T8 light bulbs during winter time. That should work for raising Tilapia with your system.

I have kept my water temp warm by using an 800 Watt water heater and two light bulbs, and so far I have not lost any Tilapia yet!!
The lowest water temp I have got is 17C
And this year we have had many freezing mornings. For example this morning was 16F which is almost -9C
Per my studies, the only fish that is good to eat and can reproduce under these conditions is Tilapia. So, that is the reason I have gone this route.
As of now, I have not seen any fingelings, I hope by April I see few.

Woaw, you are very quick to answer, thanks a lot!



Does this mean that you have to recycle the whole system every year?

The main reason why I want to build a green house is to protect my system against the frost, which could damage it I beleive.



That's great news! I have been thinking of that species because they seem to grow quickly, taste nice (and are rich in omega 3 ) . But the main question is when you say "between 14°C and 40°C" does this mean that 14°C is the lethal temperature? Because if it is the case, it is like for the tilapia and it means that the water must be around 20°C minimum for them not to be ill.



I am indeed planning to dig the ground to create a basement. Well, as for Zsazsa, the main reason is to avoid having legal problems due to the hight of the system, and problems with my neighbors as well.
I am therefore planning on having the basement of the green house burried in the ground by 1m (that is a lot of digging and I am hoping that I won't have to dig deeper!

I am also planning on insulating the sides of the greenhouse as follow :
outside - plywood/wood - fiberglass/polystyren (5cm) - plywood/wood - aluminuim foil (like in Zsasa's one)

I will also put polystyrene underneath the basement to insulate it from the ground in case it is wet to prevent heat loss, and around the fish tank as well.

Plus I will be using polycarbonate for the south facing side, with a good insulation coefficient.

I think that I will try the first year with local fish like goldfish, carps, perch, or wells catfish, in order to measure the evolution of the different parameters during a whole year. At the end of it, if the temperature of the water is relatively "warm" during winter time, I might try with more exotic fish.

What do you think of that plan?