Few things are more relaxing than a day spent by a well-stocked fishpond. The sun bright in the sky, a gentle breeze rippling the water, a small flock of ducks quaking and swimming among the reeds. It’s an angler’s dream. But it can all go so wrong. Ropy algae, stagnant water, suffocating fish. Poor maintenance can transform a beautiful, serene fishpond into something that looks more like a bog.