Backyard Aquaponics
A place to discuss aquaponics

Do you think the breed/size of the fish has much to do with it? Meaning if they are smaller, they'll hide from the other fish, bigger and they'll eat them. But if they are highly stocked, with other cod of similar size, they'll be more active?

I do remember reading about it somewhere, and most of the fingerlings for sale say to keep grading them. I have no idea about what the definition is highly stocked is though. Could be read several different ways.

Hard to say really, but the MC in my small system has certainly been of similar size to the rt for extended periods.

As I've mentioned in another thread some time ago, one commercial MC aquaculture business used to advertise stocking rates of 250kg/m^3, but they removed that statement from their website a while ago.

My 19 MC (about 15 cm) are in about 200 L of water. Obviously not a high stocking rate by aquaculture standards... and, at that size, not particularly high for aquaponics but I can't lower the level any more.

Am feeling a bit more positive about them since our weather changed and I turned the heater up at the same time... water was about 20 but now about 22 C. They're a lot more active during the day and eating about twice as much. One took a pellet from the surface while the tank cover was off today - for the first time.

They're definitely bigger than when they went in.

A couple of them seem to be outgrowing the others. Not big enough to eat their mates yet and I haven't seen any obvious serious aggression. But they do jostle each other and occasionally look like they nip each other trying to squeeze under the decreasing space available under the pump.

If grading is the go, I'll be able to move the bigger ones to another tank in a month or two - where they'll have to compete with some 35 - 40 cm jade and silver perch.