I'm in Arizona. What fish to use?

[Mike Roe]

Just bought some tilapia and have them in an aquarium while I'm finishing my system set up. It's fall here in Arizona. In the summer water temperatures can get into the high 80s, but in the winter we can get into the 50's. NOW I was just informed tha tilapia will not survive much below 70 degrees. I don't really want to build an heater for the water, solar or otherwise. But would still like to use a herbivore as a fish so I can grow duckweed to feed them and keep my "cycle" so to speak. What other fish can I use, since I'm expecting my tilapia do soon die. Attached is my system just after I put the liner in and am filling it up

[Chi Ma]

You can use catfish. If you want to do tilapia you can keep them indoors and breed for the spring when water temps are ideal. Then harvest them when the water gets cold and repeat the cycle again. You can also use blue tilapia because they are more cold tolerant than other species.

[TCLynx]

Tilapia will survive water temps below 70 F they just won't be eating or growing.

The Drop dead temp for most types of tilapia is somewhere between 53 and 55 F.

 

Now I gave up on tilapia because even in central FL in a greenhouse I couldn't keep the water over 55 F two years in a row without extra heating (granted those were to extra cold winters in a row.)

 

I grow catfish and bluegill now but they are not going to be too keen on eating duckweed.

 

Actually, don't expect to grow tilapia out fast just eating duckweed alone and you have to grow an awful lot of duckweed to feed a dozen tilapia.  A 16 foot by 30 inch duckweed pond fully covered in duckweed would be completely clear of duckweed if I threw 12 tilapia into it and didn't feed them any pellets for a week.