I got a pond kit (sunterra butterfly garden) at a garage sale and it's never been used before and it doesnt have a filter for it and i want to get a small predator for it that will be able to endure the winters here and will live of a population of rosy reds that i want to get going in the pond but wont wipe out the population. I'm going to pack it full of hornwort and water lillies to help in filtration and im going to have a water fountiantype thing in the middle of it to airerate the water. So what would be a good predator for the pond that wont get to big but can endure cold winters and wont wipeout the population of rosy reds i want to get going? I really dont care if its native or not just i want a pred..or i might just use it for rosy reds and guppies during the summer so would i need a filter for it or should i build a filter? Any advice would be greatly appriciated thnk you very much!