Keeping edible fish/crustaceans etc?

[jn]

Ok Don't think I'm mad.. but I was just reading a magazine that was talking about something they called aquaponics....basically hydroponic beds to grow whatever you fancy (fruit/vegies/herbs/ flowers or houseplants)... fed by an aquaculture system.

So it's basically a closed system, you feed the fish, the fish wastes feed the plants, the plants (and the gravel beds they're grown in) act as filters for the water. Not rocket science really.. no different to what happens when we grow plants in our tanks anyway.. except these folks were farming edible fish (it was an Aussie magazine, they were rearing perch and yabbies!)

Does anyone know what fish you're allowed to 'grow' for your own consumption?

I live in a rural area.. I've got room to try stuff like this .. The soil is very dry here,we're also water conscious so like the idea of the water recirculating and not just getting sucked up by the wind as soon as stuff is watered (and of course edible crops for us!)

So what fresh water eating fish can you have at home? (Preferably types that could be encouraged to breed!! And no I don't want to eat goldfish thanks!)

[alanmin4304]

The idea is not new as the Chinese have been doing it for centuries. The canned fish dace that you buy in the chinese shops is grown in the paddy fields I believe. I think you might have problems with the type of fish you can keep. I think giant gourami are grown for food in Asia also.

[Gannet]

do you want cold water or tropical? if you want cold you could go to a pet shop and get some koura

[anthony law]

what about saltwater crays or fish :lol: :lol:

[purplecatfish]

My next big project is converting my son's lardge sandpit into a pond. I'm going to stock it with whitebait, koura and freshwater mussels. The main reason is that it's next to the BBQ and I want to tease my Dad :lol: .

[jayci]

you can eat any fish, except the poisons ones.

[paul_r]

I saw at the fish show in hamilton that trout make good tank mates (if you have the right size tank) Rainbows are a little agressive but im sure a couple browns in a decent size tank would be awesome

[HaNs]

I saw at the fish show in hamilton that trout make good tank mates (if you have the right size tank) Rainbows are a little agressive but im sure a couple browns in a decent size tank would be awesome

I was under the impression that it was illegal to keep them(or was it to "farm" them?)

[Barrie]

another thing to remember is that it is illegal to have in your posession a fish or cray for that matter that is not of legal size or in season. I do know that a commercially farmed cray is fine but you would need to be able to prove that you got it from a farm

[jn]

I'm laughing Alan.. Yup.. not surprised the idea is not any sort of new innovation.. it's all marketing isn't it? But I suppose giving the increasing trend towards hydroponics and soilless growing it take on a new twist

I should have specified.. I'd be looking at an outdoor system, so most likely coldwater, maybe something the size of a small swimming pool.

It would also have to be freshwater since the water pumped away from the fish would go straight onto crops.

I read yesterday that farming trout was illegal, I remembered about Koura but didn't know if you were allowed to grow them for eating.

Anyone know where I could find regulations?

(Oh.. and jayci - I was hoping for fish that taste good!! Umm.. goldfish and tetra pie... NOT!)

[paul_r]

im sure if keeping trout as pets was mentioned at the fish show then im assumeing it is legal to keep as pets.

can anyone confirm weather it is legal to keep them as pets?

[HaNs]

Ill get dad to find out at work on monday

Paul: Who had the trout? They may of had a permit?

[paul_r]

there was a little writeup about keeping trout as pets near the native fish section. the tank with the huge inanga.

i cannot remember exactly what it said but it was saying about how good trout are as pets. maybe someone else can remember reading it?

[jn]

That would be great. I'm not looking at selling them. I'd even be happy to buy from a hatchery and grow them on to eating size. I'd get a permit if required provided it was affordable.

(Otherwise I'll just stick to an ornamental pond if need be and sell any overstock of the likes of goldfish or WCMM)

[kiwiplymouth]

They farm freshwater salmon in cental otago.

[alanmin4304]

Trout and salmon will not do well in a pond. They need cold running water because it is high in oxygen. Two stories I will deny under torture. The man cleaning the water races new I used to get my daphnia from the oxidation ponds for one of the local towns. Once a year they shut down the water races (which take water from the Waimakariri river) and catch the stranded trout and put them backin the river. He suggested we put a drum of fish in the pond because of all the food. You could see and hear them rising for about 18 months then they were all gone. I also found about a dozen baby trout about an inch long and put them in a goldfish pond and they hardly grew at all in 2 years. Had to get rid of them when the Maf were coming to inspect the place for importing so they went back into the river.

[rollergirl]

Mmmm smoked trout...so goooooood 8)

[anthony law]

trout make good snapper bait, :lol: :lol:

[jn]

Ok.. now those are the things I knew someone here would be able to clue me into. Thanks Alan.

Ok.. so what are other options? What else could I put in a para swimming pool sized pond that would have some use? What do people buy as bait?

Do blackmoors wholesale for more than goldfish? (and if so is it just because they are harder to breed 'well' than goldfish are?) What about barbs? Is there much of a market for them? Maybe I could breed them over the summer like Caryl does and move the breeder stock indoors for the winter.

Any other ideas? I'm quite open to suggestions I just need something to produce enough nitrates to feed some plants that will tolerate the cold and hopefully earn me something in return (or at least pay for themselves including my running costs!)

[alanmin4304]

Good quality orandas or black moors are worth money but they need to be quality. You will be lucky to get 10% good quality from breeding them as well. I am not sure how orandas will go in the winter down here as I have never kept them outside. They eat plant as well, but if you wanted to grow the vege with only the roots in water that should work. They grow lettuce and tomatoe hydropnically but I don't know about other vegetables. I am also not sure how fish would survive in a proper hydroponic liquid so you would need to work on the requirements of the plants and fish. Could be fun.

[jn]

Thanks Alan,

Here's a couple links if you're curious.

http://www.aquaponics.com/

http://www.backyardaquaponics.com/

Yup.. the setup is similar to hydroponics.. the plants are grown in gravel planter beds separate to the fish pool (hence the need for some space!). The water is pumped through to them by one of 2 methods, either by continuous circulation or by periodic flooding. The water then drains back to a sump, and gets pumped back into the pond. No hydroponic nutrients are used.. just fish water except for the occasional addition of chelated iron apparently. No extra filtration is required, the gravel beds and plants take care of that (I haven't seen a magical formula though for how to determine how many gravel beds you need or what rate to pump water through but I presume that could be tuned accordingly by adjusting stocking, planting and flow rates. Shouldn't be rocket science either, and the other half is handy electrically so could easily rig me up some relays and float switches to suit exactly what we'd need.

There are ways to set up a system apparently to use a single pump but of course this depends on gravity which means you've got to have the right location for everything (and means the water flow directly back to the pond). I'd probably favour the sump anyway as it could collect any debris that might run out of the gravel beds (say after harvesting or putting in new plants) and ensure it didn't get into the pond. (easier to clean a sump than a pond!)

I spent some time at Borders bookstore on the weekend (who needs a library!) and there's a whole heap of stuff that can be grown hydroponically including capsicums, cucumbers, lettuce, tomatoes, herbs and some flower type crops

I have a 'domestic' sized glass house that I haven't set up yet so building beds for stuff like peppers and cucumbers at knee height would allow the water to drain and also make it easy to train them for climbing, shelves are typically built on a slant and water runs into one side and out the other, sometimes trickling down from one shelf to the next depending on the setup (how efficient is that!). More beds could be setup outside for stuff that doesn't need as much shelter such as lettuces and herbs. Some varieties of lettuce should do fine in the glasshouse in the winter, and probably some of the hardier herbs too. Of course I wont' be growing carrot or onions but I can still have a veggie patch!

The magazine said that plants grown in this way do better than plants grown under a typically sterile hydroponic setup probably due to fewer chemicals and extra biological activity. Apparently the fish tend to be healthier than than in a confined aquaculture setting (perhaps due again to less use of chemicals and more natural conditions). Of course he would say that as he was promoting his book! But I can't see why it wouldn't work.

When I water change my barrel pond and use the water on the plants.. so it's all the same. Just set up more intelligently and more efficiently and I can grow more AND have more fish? Win win situation if you ask me

And if I have to add the odd bit of potassium or iron from time to time then so be it.. that stuff is pretty cheap.. cheaper than lettuce in the winter!

And the other half.. who couldn't be any less interested in fish, who has resited my pleas for a giant ornamental pond, is keen on the veggie production and the more efficient use of water, is talking about where we could put a setup....so I'm gathering all the info I can before he changes his mind! :bounce:

I agree with you, I wouldn't be sure about fancy goldfish outside in the winter either, I've seen veiltails do fine but wouldn't be sure about orandas. If I used a blue pool liner blackmoores would be easy to see so I could spot ones that needed culliong Of course they would need a shade sail to foil the birds! And I'm sure I could feed the fry culls to our chickens! (ick!) (Would blackmoores be more popular than shubunkins?)

Anyway, even if I can't grow fish for eating it would still be worth it if I can sell some fish stocks and/or some extra herbs and veggies to workmates etc!) and supply myself in the process!