Choosing Fish, Should I get a heater?

[bcp]

I just finished cycling (fishless) a 100 gallon (rubbermaid stock tank) system.  It's setup in my basement.  Currently the temperature hovers around 63 degrees F.

I would like to avoid a heater if possible.  According to the hatchery website the range for Tilapia is as follows...

Blue Tilapia  Reproduce (68F - 72F)  Can be stocked once pond reaches (60F)

How does the following density sound...

3    - Channel Catfish

20  - Bluegill

5    - Tilapia

Would this combination survive well in an unheated basement system or should I bite the bullet and get a heater?

[Alex Veidel]

That stocking density sounds a little high, you usually want to shoot for one lb. of fish per 5-10 gallons of water in an aquaponics system. If you add artificial aeration, you maybe could bump that up a little, but that's the amount of fin room a fish would be happy with. Otherwise, they could get stressed out.

What do you hope to achieve with this aquaponics system? Are you doing it for the fish or the plants. Or do you just have a desire to do something sustainable? If your purpose is sustainablilty, yeah your fish will survive at 63 degrees, and they'll definitely produce waste to feed your plants. And maybe you'll get a fish meal every now and again. However, your fish will definitely be happier with it a little warmer (at least the tilapia will), and happy fish eat more, which in turn produces more waste for your plants. They also will be at a temperature that is comfortable for producing fingerlings, which is another sustainability factor. Your less cold friendly plants (tomatoes, cucumbers, etc.) will appreciate the extra warmth as well. A heater might be a good idea for your system as a backup or safety precaution in case something happens or you change your mind and decide to try heating. How cold does your basement get in the chillier months of the winter season?

[bcp]

Thank you for answering my question.  

My goal for the system is to garden in a controlled environment.  The drought last summer made it very difficult to grow anything, even with irrigation.  I also liked the idea of year-round production.  I'll be producing mostly lettuce, possibly some beans and cherry tomatoes.

I'll take your advice and go with a heater.  My main fear was adding another failure point and the additional cost.  But using a heater I could skip the bluegill and go with all Tilapia.  Do you think 1 Catfish and 10 tilapia would be good?  The catfish are there to clean up any extra food the tilapia don't eat.  I think I will about 4 gold fish first to act as canaries in case there is something wrong in the system before I invest in the tilapia.  

[Alex Veidel]

Yeah, that should work. Catfish love the bottom of the tank, so they are a great choice to pair with other fish. If you decide to use goldfish to test your system, don't use cheap "feeder" goldfish. Since their goal is to be eaten by other fish, companies don't care about their living conditions; you run the risk of introducing disease to your system. By the way, if you are looking for a good heater, I have a friend that very highly recommends the Eheim Jager submersible heaters. They're not very expensive, one for your tank costs about $25. Here's a link.

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=23726

[Roger]

I think your stocking density may be a little too much.  I've stocked my 100 gallon system with 20 tilapia.  That's 1 fish for every 5 gallons of water.  Honestly I really only wanted to stock about 15 and bought 20 thinking some would die.  To answer your second question I probably would purchase a heater.  As the winter goes on the concrete on your basement floor is going to transfer some of the cold from the ground temp lowering.  You can always unplug the heater during summer and fall.  I originally had my tilapia in water that was 72 degrees Fahrenheit and since I've raised the temp to 78 they are much more active. 

[Kyle]

You might also consider raising trout instead of tilapia. They handle cooler temperatures quite well. 

Also, since you're growing in your basement I assume you will be using artificial lights. If you use actual horticulture lamps (Metal Halide, Mercury Vapor, or High Pressure Sodium) they will also generate a fair amount of heat, that the water will retain so it won't be quite as cool as the surrounding air in your basement.

[bcp]

Thanks, I went ahead and ordered this heater.

Alex Veidel said:

Yeah, that should work. Catfish love the bottom of the tank, so they are a great choice to pair with other fish. If you decide to use goldfish to test your system, don't use cheap "feeder" goldfish. Since their goal is to be eaten by other fish, companies don't care about their living conditions; you run the risk of introducing disease to your system. By the way, if you are looking for a good heater, I have a friend that very highly recommends the Eheim Jager submersible heaters. They're not very expensive, one for your tank costs about $25. Here's a link.

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=23726

[bcp]

I'm using T-8 lights right in one bed and T-5's in the other.   They don't generate much heat.  Eventually I'd like to get a Metal Halide.  The seedlings are a bit leggy and I don't know if the T-8s will work in the long run.

Kyle said:

You might also consider raising trout instead of tilapia. They handle cooler temperatures quite well. 

Also, since you're growing in your basement I assume you will be using artificial lights. If you use actual horticulture lamps (Metal Halide, Mercury Vapor, or High Pressure Sodium) they will also generate a fair amount of heat, that the water will retain so it won't be quite as cool as the surrounding air in your basement.

[Roger]

BCP - If the bulbs you are using are at least a year old I would recommend buying new bulbs.  Also, if your seedlings are leggy I'd drop those fluorescents as close to the plant canopy as possible.  I've had plants grow into fluorescents and the plants were fine.  Can't go wrong with a HID light though!  My 1000w is seriously outperforming my T5 fixture.

[Vlad Jovanovic]

bcp, Don't kid yourself, those T-8's and T-5's put out quite a bit of heat. It's just that the heat is dispersed along the entire length of the tube (and the ballasts of course) so it just seems like they don't. Seriously, put those T-8's in an enclosed box and watch the ambient air temperature sky-rocket. I've used them to heat an otherwise unheated greenhouse space (bubble wrap insulated underneath a sprouting table) and was amazed at just how much heat those things put out. In a 2.4m3 space with temps at about freezing two pairs of 36Watt T-8's kept up a 9-12 degrees Celcius difference...

I guess because HID's put out all their heat at one concentrated point, so when we put our hand directly under that point, we think of them as 'hot"...