Fish

The choice of initial fish was partly determined by what was available and by what species could survive the expected lower temperatures we get here in wintertime.
While I was waiting for the weather to warm up I placed a recording max min thermometer in the fish tank and recorded reasonably stable temperatures in the water. However the low point of 7.5 degrees Celsius means that most of the fish I thought I would like to keep would not be viable.
Help from the Backyard aquaponics forum lead me to decide on Tandanus tandanus ( the Australian eel-tailed catfish) and Bidyanus bidyanus (Australian silver perch).
I remember eating catfish years ago and being very impressed with both flavour and texture so that was a happy discovery. Silver perch is considered one of the really successful species to grow- very hardy and also very good eating.
I managed to find a source of supply for the catfish and so went to the Murray Cod Hatchery at Gumly Gumly , near Wagga,
Murray Cod Hatcheries
RMB 626 Sturt Hwy Wagga Wagga NSW 2650
ph: (02) 6922 7360
and bought 180 fingerlings. They were about 40 to 50mm long at the time. Greg , the owner of the hatchery will possibly have silver perch late this year and if so I plan on buying about 100 little ones then. Greg also reckons they will live quite happily with the catfish without either species wanting to eat the other.

The fish were floated in the tank in the usual way and then when tipped into the water they simply disappeared as the water was so muddy.
This was cause for some concern as I was worried that I couldn't see the fish and so had no idea if they were feeding or not. By the time the water cleared enough for me to see the bottom I was a bit distressed to see a couple of bodies there. I fished out about 10 or 12 dead ones over the next couple of days. I have also removed a couple more since. It is almost impossible to estimate what my actual losses were as the fish are still quite small and difficult to see. Some have grown quite significantly however and there is quite a range of sizes. A few are about four times the body mass of the smallest. I expect uneven growth and it is actually a benefit as it would be a bit of a problem to have all ready for eating at the same time.
At this stage they are feeding on 2.5-3mm sinking pellets for Australian Native fish as the main diet with supplements of live Daphnia and mosquito wrigglers when I can catch the same.

The pictures were taken when the water was muddy and I managed to catch a few who were silly enough to come to the surface. I am no longer able to catch them as they can see the net coming and escape like little rockets.
They look a lot like tadpoles and swim like tadpoles as well.