How do I prevent algae blooms in a pond during a heatwave?

Starve the algae by reducing nutrients — limit fertilizer runoff, clean up leaves and grass clippings, cut back on fish food, and add floating plants like water lilies or duckweed. Keep the water moving with a pump, fountain, or air stone to break up warm, still conditions and boost beneficial bacteria. Start before the heatwave hits; prevention beats cleanup.