Q. I am a winter resident in Ft. Myers, Fla., and live the rest of the year in Massachusetts, where I have a vinyl 20-by-40-foot in-ground swimming pool. Last spring when I removed the cover, I ...

Question: I am a winter resident in Fort Myers and live the rest of the year in Massachusetts, where I have a vinyl 20-by-40-foot in-ground swimming pool. Last spring when I removed the cover, I ...

Forbes contributors publish independent expert analyses and insights. GrrlScientist writes about evolution, ecology, behavior and health. But surely, the water in the swimming pools is safe, right?

Question: After every heavy rain, I find dozens of fat earthworms drowned in my pool. If I don’t vacuum them out immediately, some stick to the bottom and leave a stain that won’t brush out. How can I ...