Backyard Aquaponics
A place to discuss aquaponics

We're in the North Carolina Sandhills region -- blistering hot summers (we're on our second week with nighttime lows of 75F and daytime highs from 95 to 105F), long, mild springs and falls, and short winters where the ground never really freezes solid but temperatures do occasionally drop into the teens and even occasional single digits (F) for overnight lows.

I gather that we could have trout in the winter and tilapia in the summer. Would catfish be year-round or summer only? Would summer water temperatures in the 90's be survivable for anything? I know that temps could spike that high because the water out of the IBC we have catching rain off the roof to water the garden is that warm right now.

One of the reasons my in-ground garden is a complete bust is that the pure, white, quartz sand that passes for soil in this part of the county is desperately deficient in potassium. Would the local water have the same nutrient deficiency? If so, would it adversely affect the fish and how could it be corrected for the plants without adversely affecting the fish?

Of the 3 species we're considering, how long do they take to reach harvestable weight? How do they rank in feed conversion? And how do they rank in dressing-out percentage?

Does anyone with North Carolina (or similar climate), experience have a strong recommendation for the best choice for a pair of newbs starting a brand-new system* as we leave the hottest part of the year behind us and head into cooler weather?

And a sort of stupid question, ...

After starting the system with cheap, tough goldfish, what do we do with said goldfish when its time for them to move out and the food crop to move in?

*And how many goldfish would be wanted to get an IBC with one grow bed up and running?

hey

I found that we dont really have enough cold tine for trout and not enough hot time to raise talapia....

I raise catfish, bluegill, and koi.... gold fish are a food one also...

jT

Catfish and/or bluefill are what I plan on using as well over here in the mountains. (Using comet goldfish currently in my small test system.)

Also on your water question, your nutrients mostly come from your fish food (by way of the fish and your bacteria); a lot of people add Maxicrop seaweed extract as well to supplment trace minerals, etc.

Since I don't have the climate moderating effect you get from the ocean I probably have a bit longer a summer and a slightly colder winter (varying from year to year). I can probably count on 5 months -- May through September -- of daytime temps above 80 and nighttime temps above 60 and Dread is full of plans to build a lean-to greenhouse structure (we'll be putting the IBC against the south wall of a shed), that could probably be expected to put at least a month on either end of that.

Catfish look like our easiest option and trout seem to be essentially impossible in this climate, but tilapia are more palatable for several members of the family so if they can be done here they'd be preferred.

How many crops per year can one expect from one fishtank?

Where does one get catfish fingerlings in North Carolina. I am also looking at starting a new system in the Research Triangle area and I cannot seem to find anywhere to get them? I am interested what your experiences will be as a fellow North Carolinian.

Our local farm store takes orders from a guy who comes several times a year. You have to pre-order from him.

Check your local farm supply store to see if they've got a similar arrangement.

And if you find a place where you can get them any time please let us know since we're not going to have this thing up and cycled in time for his October order.

Count me among the tarheels doing BYAP. Just commenting here for posterity..

We're more than happy to count you amongst us Dragonstar...

I would recommend trying to go for more fish tank volume to help keep the temperature swings from getting too extreme, and I find channel catfish can get really big so I like at least 300 gallons of fish tank water for them if possible which means a fish tank of 300 gallons or more rather than the normal 250-275 of the average cut IBC.

I'm in FL so our wacky temp swings probably happen more often (going from a 70 F day down to a hard freeze overnight) which can take a system with only 200 gallons of fish tank water from a water temp of 64 F down to 34 F overnight which is too fast a temp swing for most fish to be comfortable with (I had a small system at market do that once and though all the fish in it survived, they were laying on their sides that morning when I showed up. I really should have shut the pumps down overnight that night but I wasn't expecting the freeze to be so hard.)

Anyway, I don't recommend tilapia unless you can maintain a steady water temp over 70 F for at least 8-9 months of the year without having to heat it. The tilapia don't eat or grow much with the water much below 70 F and therefore won't provide much nutrients for your plants if they are existing in the 60-70 F range and if the water gets below 55 F you are really in their danger zone.

If the family likes the flavor (or lack there of) in tilapia, then the flavor of aquaponic catfish would likely be totally acceptable. The texture between the two might be slightly different but we in general actually like the catfish better and have quit bothering with the tilapia.
Now if the family has an objection to eating catfish just because it is catfish or for reasons that catfish don't have scales (religious reasons) the Bluegill are a good choice of mild but good tasting fish. However, you are not likely to grow as many bluegill out as large, you have to get used to cleaning a whole mess of them for a meal since they do tend to be small and grow at a more varied rate. Don't get me wrong, bluegill are really good eating (and I didn't much like eating fish at all as a kid when it was caught from the lake and dragged around till getting cleaned/cooked but the bluegill from the system that are caught and cleaned ASAP are nice and mild too.)

And as JT mentions Carp (goldfish) are technically edible fish too. Of the Bluegill, Channel Catfish, Koi, and Goldfish in the system at the market during the cruel temp swing, the Koi and Goldfish survived it the best, they didn't even seem to be lying down so much. The catfish were just huddled together at the bottom trying to snuggle into the drain fitting. The Bluegill were totally stunned by the cold and would go flipping about the tank when the current of bubbles caught them. All those fish can survive freezing water but they need the temperature change to be more gradual. Don't feed the warm water fish when the water temp gets too cool. I stop all feeding when water temps get to 55 F and below. I don't feed much when the water is below 60 F. Catfish feed best when water is between 65-85 F. Reduce feed when water approaches 90 F since hot water can't hold much dissolved oxygen.

I'm also in NC, I plan on growing channel cats next year. 320 gallon IBC already in place :-)

I am located in western South Carolina, in the corners of SC, GA, and NC, not far from the Blue Ridge. I have been pondering these same questions as it seems mostly too cold for tilapia and too warm for trout. I was wondering if anyone has had luck with yellow perch?