raising fish for food? Update #109!!

[jettgirl24]

I have also heard that Tilapia are easy. There is a way that you can set it up so that you pump the water into a trough in which you can grow veggies as well. There is a former NBA player that founded an urban farming non-profit in Milwaukee called Growing Power. They have a pretty amazing aquaponics setup where they raise Tilapia and Yellow Perch and recirculate the water to grow salad greens, tomatoes, etc. You can find basic information on their system here: http://www.growingpower.org/aquaponics.htm. I found a bunch of information through a Google search on aquaponics because I am interested in it too, when I get back from running errands I'll see if I can find the links and post them for you!

 

[Crazyland]

We stocked our beaver pond with Channel catfish. There is already small mouth bass in there are gar. Err however you spell that fish, would really love for somebody to come and get rid of them all in the pond but it is a shared pond. I doubt the other owners would mind. My hubby likes the bass and I like the catfish.
I would never grown fish in the smaller of your two choices. It is just to small imo to sustain a nice population for human consumption.
Plus you want your fish to be happy right?

 

[Garden Gal]

Quote:
I'm intrigued and have a few questions if you don't mind! I have raised koi but never considered them a food crop due to the periodic treatment for parasites... how do you deal with this for a food fish?

Also - how long does it normally take, on average, to get a fish to harvest size?

Can you give a bit more info on what sized tank vs size of plants/filter you would use for someone only raising for their own use - not selling? I know this is a vague question because it would depend on how often we eat fish - but are there any basics you can share?

Many thanks!

 

[sydney13]

the 30 gallon bucket has definitely been ruled out

but what about the duck's stock tank, do you think that could work? and if i had the fish in the pond (which im think is most likely to happen) how much, if any food would they need? their is lots of buggy things and plants in the water that the fish could eat, but would they be able to provide their whole diet with that? and how many fish could I fit in the 50 gallon tank or the 300 gallon pond?

 

[Garden Gal]

Quote:
The number of fish you can have in any container / pond is going to relate directly to the amount of filtration/oxgenation provided. More fish produce more ammonia (whole nitrogen cycle you'll be learning about) and need more filtration. Even 50 or 300 sounds small to me, but let's see what White Mountain Ranch says since they actually raise fish as a crop - everything I've done is for ornamental purposes, and I've always gone "more is better" in regard to providing extra oxyenation and filtration.

 

[WhiteMountainsRanch]

More is always better in regards to filtration and oxygenation.

We raise ours in a 300 gallon tank, but we do aquaponics so there is plant material filtering the fish waste out of the pond at all times. We also made our own biological filter that all the water goes through before going into the grow beds. The fish waste has to be turned from nitrItes into nitrAtes before the plants can use them. Also, the nitrite buildup can kill fish if it gets too high (hence the cycling of a house aquarium before you put too many fish in).

We buy ours 100 fish at a time and they do well in the 300 gallon tank. HOWEVER you MUST have good filtration for that heavy of a stock load. Especially if it is fish YOU want to eat, as the dirtier the water the worse the meat will taste. The standard rule of thumb is a stock density of about 1/4 lb of fish per gallon. This would mean approx 100 full grown tilapia in a 300 gallon tank. Tilapia are easy BUT they cannot survive in water less than 50 degrees and therefore MUST have a heater. We buy ours as fingerlings (about an inch long) and they take 6-9 months (depending on how warm the water- the warmer the faster they grow) to reach harvest size which will give you two 8 oz filets from each fish. We tend to stagger our fingerling purchases so we don't have 100 fish ready all at once. We are also working on breeding them so we can raise our own fry (babies).

We are also working with Bluegill right now which you can eat and are quite tasty. We have our own worm farm which we use to feed the bluegill, but tilapia are vegetarians and therefore we grow duckweed in small kiddie pools for them to eat. There is a fine balance between how much you feed them, how fast they grow, and how much waste they produce. Feed to much and the biological system cannot overtake the nitrites as fast causing toxicity in the water.

I looked at a bunch of different types of fish suitable for aquaponics but decided against carp and catfish as they eat anything, which will affect the taste. Bluegill eat only organic worms and our tilapia eat only organic plants, so the meat tends to taste better. If you REALLY like the taste of catfish, by all means try them!

As for fertilization, we fertilize when they are babies and when we don't have fish (or few) in the system, with a standard aquarium plant food fertilizer, (Seachem) We are looking to switch to an all organic fertilizer, but there are few to none that have been tested for use WITH fish, most are developed for hydroponic use and are not food safety tested.


Hope this answers some questions, please feel free to ask me more.

 

[lil'turkeymama]

I love this plan.I have had goldfish ponds are several years.We are planning a real pond,hubby calls it pond I call it lake,right in front of our new log house.I plan on stocking it with large and small mouth bass,bream/sunfish/perch,and maybe a few catfish.Our local feed store has fishfood.It comes in 50# bags and it sure makes the goldfish grow.

I'm gonna go read awhile..

 

[mississippifarmboy]

There was a member on here from California that was raising tilipia (Or something like that). I'll see if I can locate her for you.

 

[Garden Gal]

White Mountain Ranch - thank you for the info! Have you had to deal with parasites with the Talapia, and if so, what "human safe" treatments are available? I'm really, really thinking of trying this. Do you use UV sterilizers at all? I have recently installed one on my koi pond to prevent (hopefully) parasite issues.

 

[WhiteMountainsRanch]

Nope- we have never had a problem with parasites at all. Never seen one- no worms, cysts or anything.

No UV sterilizers either, that would be unnecessary in a pond type environment. All you really need is a good biological filter and a way to aerate well. Ours goes from the tank, through a pond pump into a fountain looking thing that flows INTO the biological filter out the bottom of that into our first grow bed, out a tube where it splashes into a second grow bed, and then down a tube where it finally splashes back into the main tank, so plenty of aeration here.