Backyard Aquaponics
A place to discuss aquaponics

Can anyone point me in the right direction on growing murray cod? Did a search but not too much info really. All I can find is that they are a slow grow out fish, territorial but hides not really required and need grading. Was wondering if they are aggressive eaters or not? My water is still really cloudy from the gravel I put in so I can't see if they are feeding well or not. The smaller fingerlings in my current system do not seem to be feeding (although it has only been 3 days since I put them in). No deaths yet in the old system but can't tell if any are dead in the new system.

Any murray cod info welcome!

Quachy

Only have the one. George likes his own tank and live food. He may eat pellets but I have never witnessed this. And he will kill any fish reguardless of size that you put in with him. But he prefers ones that will fit in his mouth. He spends all his time on the bottom near the side doing nothing. If he gets company he is probably the fastest fish I have.


If you are going to keep them I think they need to be keeped in a group so they don't hunt each other down. Long grow out times and expect to lose a lot of them. Sleepy Cod are also a long growout.

Cheers duff, John from Glenwater where I got them from said that they would take pellets fine and that they should grow pretty quick in the warm weather, but all I can see so far is what your George is doing, sitting on the bottom, doing nothing. I threw in a worm and bang it was gone as soon as they saw it hit the bottom. I didn't throw in any more so they don't get attached to live food.

Any tips on getting murrays taking pellets?

Quachy

Only if they are hungry enough and none of the other fish will fit in there mouth they might take the pellets. I also throw in small bits of fish from fillets in the freezer. And I get some yabbies every now and then for him.

The Murray cod you got from Glenwaters should have been wean on pellets.

If you keep them at high densities this will reduce cannibalism. Mortality rate is around 80-90% and it takes 10-12 months to grow them out to 600-800gm in a recirculation system. Take into account that a recirculation system will have top water quality so don't expect a growth rate like that.

So quachy, did you put hides in? I also got mine from John and he said make sure you add hides. Thoughts here are that you shouldnt use them as it will help keep them from being territorial. I'd be interested in what you have done.




What do you mean by dont expect a grow rate like that in a recirculation system when you say it takes 10-12 months for 600-800gm growth??? I'm confused.

I think he means in an aquaculture environment the water will be top quality, so the fish will grow out to 600-800g in 10-12 months, but in an ap system they are gonna grow slower than that.

No hides in my small system with the 50 murrays, I can't see them feeding but I'm guessing that they are. My water results are
ph7.2,
ammonia 0
nitrite 0
nitrate 80

I just harvested a lot of vegies and it's time to resow.

Murrays seem fine and no deaths so I'm guessing that they are ok with the nitrate level. There have been no other fish in the system since Sunday, so I am guessing that they are feeding as the system is still producing nitrates and all others are at 0.

I have put hides in the big system with the 35 bigger murrays, but I can't see them due to wter still clearing up.

Will keep you up to date as I get more data.

Quachy

don't panic until your nitrate are a lot higher than that.

Higher? How high is high?

a guy I know running lots of trout currently has nitrates over 500 and they are thriving. long term exposure probably causes issues. unsure how much cod can handle. I know silvers will feed fine up to about 300 parts.

I guess I wont rush then if I don't need too. Was going to sow seedlings, but after knowing this will go half half, seedlings/seeds.

Thanks for the info.

Quachy

Just keep an eye on your ammo if they cod are not eating it might build up.

Getting some plants going might help clear your water up.