Advice appreciated

[Dallionz]

You can see the two tanks and the fish I have in each tank in my sig. My three black skirted tetras in the smaller tank are there because the danios were biting at their fins horribly. The three little black skirted tetras have been doing great in that small tank since I moved them and look healthy again. They've been in there for a good three months.

Now to my problem. In the time they've been in there, they have not grown. And they are pretty small - probably 1/3 the size of an adult. Also, that tank is not heated - not an issue during the summer but now that winter is approaching it will be. I'm wondering if I should put them back in the 55 gallon. If I got a couple larger black skirted tetras for the younger to school with, would that deter the danios? What should I do? The little tetras seem pretty happy in the small, unheated tank but their lack of growth concerns me.

Does anyone have any suggestions? Do I need to move them at all or do black skirted tetras just grow slowly? Any thoughts?

Thanks in advance.

 

[Lateral Line]

At lower temperatures, fish metabolism slows down, they will generally be less active and grow more slowly. I don't know what temperature you have in the unheated tank so it's only a guess.

 

[JustinSane]

What are you feeding them? One reason could be that their diet isn't diverse enough.
It's also possible that they are suffering from some slowly developing internal parasites.

 

[Dallionz]

I feed the black skirted tetras flakes and then they also munch on the algae tablet I drop in there once in a while. I have been watching the temp and while the small tank is not heated, I haven't seen it go below 71'F.