Yes on floating up. I keep a marble stone in each basket to hold them down when the pump is off. Not crazy about adding to landfills either, but these hairnets are pretty insignificant in the grand scheme of things which include tons of plastic water bottles, MacDonalds trash, and Keurig K-cups each day (I use the reusable K-cups and my favorite coffee which I dump into the flower bed when used, so maybe that compensates for my hairnets.) I back rinse the hair nets every day or every other day, depending on how much stuff has blown in. Typically a disposable hair net lasts a week or ten days before I have to replace it, so my landfill impact is minimal. The hairnets catch a lot of pollen carriers, but the pollen itself, not likely. It's the other stuff that otherwise goes through your pump basket and onto the main filter cartridge that the hairnet stops, that really helps a lot. Last time I cleaned the four Pentair filter cartridges, there was very little I could see on the cartridges at all.
