Keeping Cool Water Fish w/ Tropicals

[10 Tanks]

Hello TFF...

I've been keeping Comets with my Tetras for some time. I got the Comets as fry and raised them with adult Tetras. I keep my house temperature at 72 degrees, so there's no heater in my tanks. The fish are all roughly four years old in this particular 60 gallon tank. Anyone else combine cool and warmer water fish?

10 Tanks

 

[WhistlingBadger]

As long as their preferred temperature range have a good overlap, it's probably fine. I kept turquoise rainbows (a "tropical" species which prefers cooler water) with goldfish for several years until the goldfish outgrew the tank. All were healthy, active, frequently spawning, and disease-free.

As always, do your research. Keeping any fish long-term at the edge of its temperature range is not advised. In other words, if Seriouslyfish says a fish should be kept at 75-85F, keeping the fish at 85 for years is probably not going to result in the best health. They'll probably survive, but they'll do better if kept toward the middle of that range, perhaps with occasional fluctuations to the extremes.

Some fish are so adaptable that they just don't seem to care. Comets fall into this category, seeming equally at home anywhere from 50F to 80F, and able to survive quite well down to just above freezing (though they stop eating and go into a near-hibernation state, and they can be more prone to parasites at the upper range).