Holly,
just look for something that is hideously ugly, and that is a dragonfly larvae.

I went and looked at them, you are right really ugly. But I have seen them before, so now I know what to look for.

I jerked my hand out of my lily pot fast, the first time I saw one! Now I know they are my friends.

I also put the lilies in the deep part of the pond. I actually got one this year that bloomed a fair amount (for our weather which has been unusually warm this summer) and was a nice yellow. The marsh marigold will go into the vegie bed again this fall. The water celery actually sends roots down deep in the rock and seems to come back on its own.

I realized I never came back to this thread after looking up info on tadpoles. I thought they would eat both algae and "prey," and it turns out they do, but at different points in their life cycle. Smaller tadpoles stick with algae. Once they start growing legs and turning into frogs, though, they become carnivorous and will eat anything that fits into their mouths.

I have 5 fat late-season tadpoles in a clear plastic container in the house right now. We fished them out of one of the water garden pots just before the first frost. We've been rearing a few in the house all summer, letting them go when they turn into frogs, catching a couple more... but I'm not sure what to do with these. I'm hoping they'll metamorphose before the weather turns really cold, so they can be released to go wherever tree frogs go for the winter!

My water poppy pots are buried in the raised beds and they have a nice cover of snow. I pulled the lily pots and shook out the lilies. Then put them in a pot that is open all the way around with a grid; then put another on top of that to opening to opening, then wired then together. The pots are small only about 8" across. Tossed them in the deep end. Much better than trying to lug pots filled with soil and rock out in the spring. We'll see if they do okay over the winter. Assume they will go to sleep like the fish.

Pond is set for winter so now the long wait.