I was happy to read about Fountec, but then read that a surfactant in it will harm flying insects. My fountain reservoir is buried, top is a concave tiled disk with holes for recirculation. The bees and wasps come frequently for their water needs. The bees activities are wonderful - they float on the water, doing a half circle or so, then fly away. Definitely don't want to cause harm to beneficials. Would like to figure this out. Here's what I got from a web store:

Quantity :

Price : $ 9.95
Weekly Fountec use also prevents mosquito landings! Fountec is not only a powerful algaecide and clarifier, it is also a surfactant that breaks water tension. Due to the natural effect of Fountec's polymers on water tension, it is an excellent deterrent for control of mosquitoes, flies, and wasps in fountains, water gardens and birdbaths.