Hey, Jim, you could try dipping the water into a container and running away from the lake shore.. or use deet. I like my Katadyn Siphon filter. Easy to wipe clean, 5 quarts per hour. (1 pint in 6 minutes) With a little planning you can have water ready when you need it... and with no pumping or broken pump handles. The Siphon filter does its thing while you set up or break down camp. With a 0.2 micron ceramic filter it does a pretty good job of keeping the gut-eaters out of your drinking water. If your water supply is stagnant, has things peering out at you from below the green and fuzzy surface, or if it's located down hill from the local pig farm, just add a little Micropur before filtering to be sure. Brum