Hey there -- my newts do not live with fish, although I do have a small, separate fish tank (10 gallons) and I acquired a baby Rubberlip Pleco about two months ago to control the jungle of green algae strands that were getting totally out of control. The little guy is an algae-eating MACHINE. In general, my research recommended this species for small tanks because it only grows to about 5 inches long, and because unlike common plecos, it can survive totally on algae and doesn't need other foods later in life. I found it in the second Petsmart I looked in. It is hardy, a little ugly =D But TOTALLY WIPED OUT the algae problem by its own little self. I never expected that and would recommend this small, efficient species to anyone. The only downside I've found is that now, rather than algae, I get cloudy green water sooner from the ever-increasing poop of the Rubberlip. I don't have a clue how it would act with newts, but its been very peaceful and shy around my fish.