My small fishpond looks its yukkiest this time of year. Full of debris, dark in color and still with its deicer in place, it looks uninhabitated. Not So! Under the mire are frogs still a-slumber, and goldfish slowly swim its murky depths. I won't clean the pond out until the frogs emerge from hibernation several weeks hence. But since the nights are now above freezing, it's time to remove the deicer that's been plugged in since early December. The 6" round green disk floats on the surface, keeping a space ice-free, and thus allowing the gas exchange which permits fish and amphibians to survive the winter.
My 8' circular pond, only 18" in depth, has been in place nine years now, and remains a source of joy. Not too much maintenance is required. I give it a good cleanup in April, run the waterfall regularly in the warm months, (which keeps the water oxygenated) and rely on barley straw (available at Gardener's Supply, among other places) to control algae. A couple of times a season I do have to scoop out a layer of string algae, but that stuff gives an aquatic boost to the compost pile.
I learned the hard way how not to kill overwintering frogs. After the first disasterous winter when I had to have Courtney's boyfriend scoop out carcasses come spring, I figured that since my pond has a butyl liner and therefore no mud into which to burrow for hibernation, I had to do something else. Here's what I did:
First, I left the autumn debris in the pond. I know, I know, this runs counter to what the books tell you. But the layer of junk gives the frogs something to live in. Second, I sank a plastic dishwasher pan of clean sand into the water. (It comes out in pond cleanup in April, & is stored in the shed.) Since I've been doing these two things I've seen no more dead frogs in my fishpond.
The pond, with its murmuring waterfall, glistening fish, and regal green frogs, is an oasis in my garden. For a few paltry hours of maintenance I get sound, color, and livestock. A worthy deal!