Whats a good way to keep a backyard pond clean of algae?
The best answer is also the most expensive. There is an Ultraviolet light filtering system. You clean your pond in the spring, plug this sucker in and no more algae. Than you pull it indoors for the cold weather and start over next spring. The chemicals work if you stay on top of it, but one missed dose is all it takes for the algae to reappear. You also have to be careful to get chemicals safe for fish (and pond plants if you have plants). I never had much luck with chemicals. The uv filter is worth the investment.
