Of course, I can use tropicals as pond fish here but perhaps you can too if you winter your lilies. I use Mollies and Guppies for mosquito control, they are ravenous all the time and small enough to escape the view of water birds. I like the fancy tailed guppies but I've found that over time and generations they regress to mainly grey. The Mollies are the best at scavenging for anything that falls in the pond that might be food. They also eat some algae and they survive without me feeding them in my outside ponds. I do feed them occasionally but not regularly. As a side benefit, they will give you a pedicure if you stick your feet in the pond!
