Backyard Aquaponics
A place to discuss aquaponics

Steve, Les is correct - no email- and be aware that it is not possible to have a short conversation on the phone with Greg. Very experienced in fish farming and quite happy to share.
Current shipping charges are $33 per 100.
I also misquoted the price- should be $2 per fish plus GST.

And plants as well now well on the way- we have even eaten a few of the thinnings.

thanx jim

I'm with you JIm, the TT's look great

Short update.
Water has finally cleared- actually crystal clear now. The growbeds look muddy on the top but the extra filter has taken out all the suspended stuff. Actually I think a fair bit of the really fine stuff might have floculated out as there is a layer of weird stuff on the bottom which when dried out has no real substance.
Fish are clearly visible but impossible to count- I think I might have lost a fair few- I did pull out about a dozen bodies in the first week or so. At that time I couldn't see the bottom so any number might have simply died and decayed into the system.
Can't catch the fish now for photo opportunity as they are much too fast for me. And as the tank doesn't get much sun it is too dark for in-tank pictures.
Amazing variation in size and colour of remaining fish- the biggest must be four times the body mass of the smallest. Some are dark while others are so light that their camouflage is almost perfect.
I now have a new potential problem- nitrate levels falling due to too many plants. I have started a new thread and am looking for ideas please.
http://www.backyardaquaponics.com/forum ... 4977#94977

Another update on progress to date.
This AQ is really quite addictive. I am sure most of my friends are beginning to think I must be a bit potty. However I know I am with like minded folk in BYAP who can happily sit and just watch their fish for ages- how tragic.
The stuff below is basically from my blog with a few modifications as the people on this site probably have a better idea of what is going on than my friends for whom I created the blog to make explanations easier

So-- from our system we have now had quite a few feeds of sugar snap peas, Tat soi, lettuce and pakchoi.
In fact the first crop of tat soi has all been consumed and a second crop is now on the way. The sugar snap peas don't look great but they are still producing a few pods. We will soon be cutting off the plants- planning to leave the roots in the gravel so that they will release the fixed nitrogen back into the system. I am assuming that the nitrogen fixed by legumes remains locked up in the roots until the plant dies??
Having a little bit of leaf eating grub problems- probably the white cabbage moth- not a major problem yet so I don't think we need to do anything drastic. Any grubs I see will become fish food and that is really just extra protein.

The fish are growing a bit slower than I had expected- now perhaps 60-80mm long and looking very healthy. I have even worked out how to catch some for photo sessions. Used a yabby trap which was simply left on the bottom for a day or so for the fish to become accustomed to it . I then dropped what has become a preferred food- chopped earthworms- into the trap which I lifted quickly out of the water. Caught about 20 or so very vigorous little catties. They now look more like fish than tadpoles.

I had thought that I might have had a problem with nitrate levels and this has turned out to be the case. However I was a bit worried that the levels would be too high whereas in fact the level had dropped to almost nil. This would not be a problem if I had a population of large fish. However my fish are very small and the growbeds are quite large and so the fish poo seems to be unable to keep up with the plant's demand for Nitrogen.
So I have started adding extra Nitrogen in the form of urea. I bought a box of pure urea from a garden supply centre and have begun to add 4g per day to the fish tank. Fortunately it looks like urea is much less toxic to fish than ammonia and so far this seems to be the case with my fish. I decided on 4 g per day on the basis of it being 1 ppm for the 4000 litres of water. I am assuming the biofilm is converting the urea to ammonia which is then being converted to nitrite and nitrates in the usual way. After a week of adding 4g per day I now have lifted the nitrate level back to about 10ppm while the ammonia level is still Nil.

Despite the potentially low Nitrogen levels the tomatoes planted in November have finally flowered and have begun to set fruit. Still only the size of marbles but I reckon the extra N will get them away and we should be able to start picking tomatoes with a couple of weeks.

what do you do with catfish after growing them? Are they edible?

It is along time since I ate catfish but I remember it as one of the best eating fish I have ever tried. My father used to catch them in the Darling river near Wilcannia.
This is my first aquaculture crop and will it probably be a year or so before they are plate size. They don't have scales and do have venomous spines so some care is needed when skinning and cleaning them.

we used to catch them on the murray and Little Murray near Swan Hill. Just remember to watch the barbs when you fillet them. They are one of the best eating fish.

sorry if I have missed it but I did a bit of a google on tandanus and the sites I looked at all said something similar to


Is this what your research has stated or did I just fluke a couple?

looks like you are helping the conservation effort as well as Carp are apparently destroying or out-competing the catfishs habitat

I've seen a great many in a tank together (and am told they taste fantastic, I also read online that they're meant to be one of the best tasting freshwater fish. Also that the ozzie one is the largest of it's family)
They grow as slow as SP, or perhaps slower. dislike floating food, and are as for community fish - they mean don't put them with smaller herbivores. They would work fine with SP, as long as they can't fit them in their mouth, however tend to prefer to scavenge off the bottom. They generally wont hurt each other. As I said I have seen 10 250mm long in a 2" tank together in my old aquarium.

I've got about 3 tantans and since the trout have gone and the weather's warmer I often see them come to the surface when I feed them. I've had them for almost a year and the biggest one is somewhere around 12 cm. Whenever I see them I wish I had more.

Ahh KE, it could be because I always kept other fish that they would stay low. Used to do crazy things like sit quietly on the bottom, then suddenly shoot to the surface, breach and come back down... lack of DO maybe? It was weird :-)

jim. interesting idea with the urea.

good to see that you have used a sensible amount of 1ppm per day. are you still measuring ammonia while you're on this regime?

i have a very strong suspision that the urea will be converted to ammonia within a day or two................but as long as you're keeping the level constant the bacteria in an established system will have come up to speed

Sounds like you have a good approach for your nitrates. Good thinking. I was worried when you said you were leaving the pea roots in the system, but that's good thinking too. Especially if you keep a few worms in there.

Catfish have limited ability to gulp air and absorb it--I forget the exact mechanism they use, but it means that some of them can go quite long out of water. During an aquarium transport, I couldn't find a "Talking Catfish" (they croak). I shrugged and kept going. 8 hours later, with all other fish back in the aquarium, I decided to go ahead and put the ornaments back in. Turned out the Talking Catfish had made the trip inside a plastic Grecian urn with only a hint of moisture. They are very spiny, so there was no problem with the skin drying out. He lived many more years.

Fresh catfish is quite tasty, although I decided against catfish in my AP system because a taste test of frozen catfish from the grocery was fishy tasting to me. My parent fixed catfish a couple months ago that was outstanding, so if I get tired of tilapia, I would consider catfish as an alternative. Here, it would be Channel Catfish probably.