Backyard Aquaponics
A place to discuss aquaponics

Can I put red swamp or signal crays in the same system as trout? Do I need seperate tanks or a crayfish condo- http://www.bluecrayfish.com/crayfish_condos.htm
Will trout eat crays or vice versa? What about feeding?
The two species thrive in the same water temperature for your information.

You can keep both signals and red swamp together, but make sure you have PLENTY of hides for them. Crayfish are extremely vulnerable after a moult (shedding the shell to grow).

As for keeping fish in with the crays, you would be better off creating a horizontal division that the fish couldn't swim below. Crays will take nips at fish given the chance. And many fish LOVE crays, especially when they are soft shelled after a moult!

been thinking about the method u suggest, myself rassd71. If u had a mesh cover over some sort of frame with say 15-20cm clearance from the base of the tank, you could seperate ur fish and crustaceans. (Think saucepan lid, but with say 10mm wire as lid so food scraps can fall thru.) Your "crusty cover", another one for the dictionary, needs to fit neatly inside the internal circumference of ur tank. You could build them in 2 halves to make it a bit easier to get them out.

The only issue i see is how do u harvest without disturbing ur fish? I guess u could simply harvest or move ur fish to another tank when ready to catch ur crays.

It depends on the shape of your tank. IF it was a square tank, you could hinge the seperator and use it to enclose the fish to one side when it's time to harvest crays.

And the 15 - 20cm (5-7 inches) would give enough room. But again, you would want plenty of hides. Pieces of PVC pipe would work well.

Great idea. Now how to adapt it to my circular tank, (scratches head.)

Photographic evidence :



The crayfish was about the same size as the Murray Cod. The cod sat on the floor of the tank for 3 or 4 days digesting him. You can see the very profound lump in his belly.

Oh, man that sucks!


As for adapting it to a round tank... PVC is great because it will curve! It would take some experimentation, but I'm pretty sure you could make it work.

i had a bass die from eating a large bluegill.

I discussed at some length (with the shrimp farmer) this subject precisely. The answer is to put your fish in a cage as large as your system can tolerate or as much as the fish may need. They actually work together very well if you can protect them as such.

This is part of the answer to the other thread I will give soon, concerning raising Red Claw intensively.

Another option for keeping them together...

http://kens-fishfarm.com/bream_cage/default.asp



Instead of seperating by containing the crays, contain the fish.

that would do it, that can be home made much less expensive

it would also give the crays something to climb on and maybe even out

ABS is buoyant enough to hold up the mesh too. You could use a larger grid mesh, just so long as it's small enough that the fry can't get out. To keep the crays from getting out of the tank, just keep the water level at least 6 inches below the edge. That way even if they do climb the mesh, they can't escape. And crays are the Houdini's of the animal kingdom.

TT, you could always adapt the AP divider (make it horizontal)

make a frame of 20mm conduit (bends easily), cover it with gutter guard (that's in the tool kit) and put in some Tees to make legs to keep it off the bottom (must be my next project )

yeh, murray cod make light work of yabbies!