Heating the whole room is really the only way to go.
Also may I suggest doing some LARGE DIY tanks in there. I had a fish room once and let me say that one or two LARGE tanks is much more rewarding and satisfying than a bunch of smaller tanks. Easier to maintain too.
Also may I suggest doing some LARGE DIY tanks in there. I had a fish room once and let me say that one or two LARGE tanks is much more rewarding and satisfying than a bunch of smaller tanks. Easier to maintain too.