Backyard Aquaponics
A place to discuss aquaponics

I would like to ask for your advice. I am planning to build a new system in Central Europe, where winters are relatively cold for aquaponics. I plan to establish the system in a natural cellar beneath our house, where the temperature never goes below 10C (50 F) and never goes above 17C (63F). I will use Led lamps.

I read a lot about aquaponics, but there is one thing about which I am uncertain. I know that 10C is high enough for the bacteria not to die out in winter (and it is also sufficient for the trout to survive), but I do not know whether 17C is high enough to cycle the system and start the whole procedure. I read everywhere that bacteria prefer anything above 20 C (68 F). I do not want to heat the water because that would be just too expensive, and producing vegetables at such an expense would never be rentable. Please, do not advise me to move the system out for the summer because that would be too complicated.

My second question is related to this one. Let’s suppose I can cycle the system. And then, what can I produce? Only those vegetables that prefer cool water, or even tomato (which, I know, loves warm water). Growing tomatoes would be a rather crucial goal.

Do you have experience with such locations that are neither cold nor warm?
I would appreciate any feedback
Best!

I blang, welcome to the forum.
I don’t have experience with your temps however I think that your system should cycle in those temps just a bit slower.
I’d imagine the led lights would add some temperature also.
Most of the ‘plants won’t grow’ threads are indoor systems so choose good lights and research the plant side growing under lights. The fish side of things look after themselves provided you use a good quality fish food.
I’d like to see your natural cellar under the house.

Find out what the water temperature would be at the coldest time.

Cycling the system with cold water temperatures would take longer to cycle.And if the water stays around 10C/50F (once cycled),the bacteria wouldn't be working all that well.The nutrients would take a lot longer to covert into usable ones for the plants.

A thought is to put a heater in there just to cycle it & then see how the plants do with the cold temperatures (bacteria).
Tomatoes are greedy plants,they will consume the nutrients quickly.At such low temperatures,the bacteria may not be able to produce it in time.
You can grow almost any plant because it's indoor,no frost in winter & cool in summer.Perfect really.The water temperature is the problem.

skeggley you beat me to it as I was writing

Now you tell me!
Your input is always welcome 7341, you always have good advice, usually it’s me that has nothing to add.

Thanks a lot for the kind welcoming words and for the advice!

The cellar is a result of heavy mining activity in the area since the 18th century; limestone has been exploited here. Later, people lived in the cellars, and lately, there are just cellars to store wine or produce mushroom. We do not use it for anything (it is wet, not suitable for storing wooden furniture), and aquaponics would be a nice raison d'etre for the cellar. Also, there is a well in it, so even the water supply is there. I attached an image.

As for the led lights: thanks, again! I am very well aware that cheap lights would not be a solution, I am just reading scholarly publications about growing plants in led lights, and I am probably going to buy the not so cheap growing lights.

Too cool, I want one.
Keep us posted.

Stop it,you're going to make me blush

And I said this for my 200th post

Fans & fresh air will be needed too.Any idea what the humidity is in there?

Fans are a good idea! Humidity is 80%,

Tomatoes aren't keen on such high humidity.
You might need to find a way to keep the humidity down.

Dear Guys,
thanks again for your kind answers, they were really helpful.
Now I have one more question.
I can use tapwater for my system, nothing is wrong with that, but since there is a well in my cellar (27 m deep), it occured to me that I could use its water. I have a pump in it, I water my garden with this water.

I have it tested and there are three problems with it (all other values are ok):
Ph: 8
Nitrate: 175
enterococcus: 4

I guess, Ph is not a problem, I can change it easily, following the advice of the aquapoincs handbooks.
High nitrate level would be a problem if we drank the water, however, in an aquapoinic system, nitrate is produced in anyway, is it not?
enterococcus should be 0, I understand, but I have no idea how high this '4' is.
Please, give me advice: is it safer to use my tapwater, or the above values are not so problematic for the fish (provided, of course, that first I cycle the system appropriately).
Best

Sorry, I did not give the units.

Nitrate is 175 mg/L

Enterococcus is: 4 / 100 ml

I would appreciate any feedback.

I also started wondering whether I need any fish to add to my system. I know this sounds absurd, but having an endless nitrate rich water supply, the question should be asked: can I set up my system without any fish?

Certainly the high nitrates will allow you to have lower stocking levels if you are doing regular water additions. If you aren't doing regular water additions, then you also aren't adding more nitrates.

If the water has too much buffering capacity and the pH doesn't come down, it could be a problem. You can still use it but you'll have to either spray apply the iron or use a type of chelated iron that is available at the higher pH (Fe-EDDHA for example). I've also noticed that plants seem to grow a bit slower with the high pH.

To me, those enterococcus levels indicate that there is perhaps fecal contamination which is not a good thing. You can use it as is but not for drinking, swimming, or bathing. These types of organisms are very common in the environment and are normal flora of the gut in humans and animals, which is why they are used as a fecal contamination indicator in water quality. My thinking on this though is that the enterococcus levels should drop pretty quickly after running through the aquaponic system for awhile (especially after the biofilter is mature). Most of these organisms are harmless but not all (If I remember right, some are human pathogens, some are fish pathogens and some are plant pathogens - still the majority do little or no harm). If you use this water then use good common sense - wash hands and wash any produce in good clean water (I think doing this is a good idea for anyone working with an AP system no matter what water they start with). Some light reading for you regarding this - https://urbanagnews.com/blog/news/food-safety-and-e-coli-in-aquaponic-and-hydroponic-systems/

Toward the end of that article you will see this comment - No pathogens were discovered in a mature coupled aquaponics system during 18 years of continuous research in Canada since 2002 (Savidov, personal communications).

Now perhaps the best way to deal with this is to shock chlorinate the well to kill the bacteria. Assuming the well head is indoors (in your basement), I don't know if shock chlorinating this is a good idea and you should check on any health hazard this might create in an enclosed space. If you find out it's OK - Here are instructions for shock chlorinating a well - https://extension.uga.edu/publications/detail.html?number=C858-4&title=Disinfecting%20Your%20Well%20Water:%20Shock%20Chlorination

Hope this helps

Some great answers, as for me the temp at 17c is ideal for growing leafy greens, lettuce will thrive at that, as for Tomatoes they need night time temps in that region to set fruit, iam not sure if the temps are constant at that, shouldn’t make much difference i think.
Humidity will have to be lowered and as already posted fresh air movement is essential if you dont want problems, if you use fans i reckon it will have the negative effect of dropping the temp as well, that needs some careful thought to get it right.

Certainly the high nitrates will allow you to have lower stocking levels if you are doing regular water additions. If you aren't doing regular water additions, then you also aren't adding more nitrates.

its not just nitrates that come from the feed to plant ratio, its all the other nutrients as well, if you lower your stocking you will also have to reduce the amount you grow and the Nitrate level you have is far to high for your requirements.
All in all i reckon its a fantastic place to have a system with some great opportunities.