Backyard Aquaponics
A place to discuss aquaponics

With all of the excitement about bulding my aquaponic system, my plans changed from having 2-3 smaller tanks to having one large tank. I didnt stop to think about some of the ramifications. Now I'm starting to wonder about the pros and cons of having different fish in the one tank. At the moment I've got Tantanus Catfish and silver perch (all fingerlings) in the same tank. What do I do next year when I want more fingerlings, and I dont want the catfish to eat them? Does anyone have an inovative way to seperate fish in the same tank?
On a similar note, I had thought about getting a few trout to grow out over winter. Can you mix trout with the above, assuming they are about the same size?
Is anyone mixing adult and juvenile fish, of the same or different species, in the same tank?
Any tips would be greatly appreciated

When I was studying aquaculture one of the tanks had Trout, Silver Perch and Tandanus in it. I never witnessed any problems and they all seemed to get along fine together as they were all of a similar size.
You could expect problems adding juveniles with larger fish as both Trout and Silvers will eat the little ones. I think the Tandanus would be ok though as they are not renowned as fish eaters.
The trout being the keenest feeders will get most of the food and grow quicker than the others so you could eat them in the Spring then eat the Perch in the Autumn and re stock again.

You could put moveable barriers in the tank. Something that would let water flow through but not the fish.

Trout man, so i can dump some rainbows in with my tandanus and silvers?

TM, do you have much info on temps for the tandanus? specs say 2C to 32C but i'm sure that max tolerable, i wonder what range they would be HAPPY at?

Some of this info is hard to find.

This Tandanus Article suggests temps up to 38 degrees and breed at > 24 degrees....

Don't know if they were the same family of catfish, but I've pulled them out of the Roper River
(about opposite Groote Eyland) in the NT....

Air temp >45 / Water temp >30 i reckon

I've had a real mix of different species in my tank at some stages, black bream, silver perch and murray cod all survived fairly well even thought there was a fair amount of size variation.. I think you need a fair difference in size with most species before they will eat each other. I've not seen a fish attack another one that was too big to fit whole into it's mouth.. Except for when a fish has been sick, then the others will sometimes attack it... That can be an easy rule of thumb for many species, if your fingerlings are to big to fit into the biggest fishes mouth, your fairly safe.... If they would fit into their mouth, watch out.....

natures way of keeping their ocean clean by eating the sick ones.
amazing how one of monyas fish had one whole fish hanging out of its mouth, the one being eaten was only a bit smaller.

i reckon the muzza cod is an exception angry fish they are

mmm... they have a big mouth.. wonder if it is anything to do with their place on the food chain?

or how developed they are?

Many fish will eat anthing that fits conveniently into their mouth.
Movable barriers would work fairly well, or even something like a mesh floating bucket. I don't recall if you have lots of access to your tank, but I think you had access in one end. If you could set up a mesh bucket or run a screen the length of the tank, you could subdivide your tank accordingly.

I've had to remove the Black Bream from my tub recently as it mauled a goldie to the point that it could not swim.
The goldie was the same size (if not bigger) than the bream.
I may be that the goldie was new, only been in the tub for 3 days or that the bream just has a bad attitude

Yeah Steve I cant see why you cant put a few Rainbows in with your Silvers and Tandanus. I think it depends though on the size of your Silvers as I recon they would go for a small trout.
Information on Tandanus is real hard to come across, as in WA at least no one I know of is doing them in Aquaculture. The reason for this is that the local species Tandanus Bostocki is very reluctant to feed on pellets.
Cant help you with the temp range sorry though as Rupert says they spawn in spring when water temps reach 24c. Hatching of larvae occurs a week after eggs are laid in water with temps of 19 - 25c.

Yeah, goldies don't really count gnash.... I think that many other fish probably think that goldfish are a little like a sick fish, very slow moving, wierd fins, can't fight back at all... Kill it....

Thanks all

I have something in mind as a net bag, its kind of like a collapsable net bag, round with a spring running through it, when it opens up its about the diameter of air con duct and about 700mm high. Its currently being used as a toy box - gotta convince the kids to hand it over.

Troutman how big/old would the trout have to be when I purchase them in autumn, so that I can eat them in spring?