As a kid I kept newts in a fish tank, shallow water with moss banks, they semed fine, I fed them small worms which they seemed to enjoy.  I maybe wouldnt do it now, back then I didnt appreciate that they needed to leave the water after breeding so i kept them longer than I should have.  But, that said they were fine. Perhaps a larger tank with raised areas out of the water, but to be fair, they dont do much to be very interesting.

These days I prefer them in the pond, I can go out at night and watch them by torchlight in the shallows.

Hi newt keeper

there is no need to keep the newts indoors as you can hopefully attract them to your garden by putting in a small pond

My dad has newts in small tanks in his shed where he breeds up some of them over the spring and then releases them back into the garden ponds once they have laid their eggs on vegetation.

He feeds the larva on blood worm, daphina etc and they metamorphose into efts and he then releases them into the garden

He only has a few pairs at a time while the majority of the animals are left to roam in his garden

I suggest that going out looking for newts during the night with a torch and then watching them within a well constructed pond is the way to go......

JC