The AquaClear sounded like a good idea, but it comes over the edge of the tank, and kinda hooks onto it, and they can't not have a hood. I would cut a hole in it, but it's a plastic one that would snap as soon as you put a blade to it.
A small, silly problem, but one that makes all the difference.
Does anyone know any small internal filters that will not break the surface of the water much (the newts like fairly still water) and can be hidden quite easily? I may start a thread asking about the filters, as this question may not be noticed right at the end of this thread. :D
Thanks everyone so far.