How to Get Rid of Spiders in Pools
Perhaps the last thing you want to see before jumping into your pool is a cluster of spiders swimming about. Fishing spiders often inhabit pools in search of food and shelter. And if you think you saw them walking on water, you weren't wrong -- these talented arachnids have small hairs on their tarsi that allow them to skim on the water's surface. Short of abandoning your pool all together and allowing the spiders to take over, there are a few things you can do to get rid of the eight-legged water dwellers.
Skim the spiders out of your pool with a net. Choose a net that has small holes to prevent the spiders from falling out. Empty the net as soon as you catch a spider and kill the spider with insecticide You could also dump the spider in a location that is far away from your pool, if you'd rather not destroy it.
Trim any bushes or vegetation around your pool. Spiders hide in vegetation and search for prey. If the vegetation is eliminated, the spiders have no reason to spend time in or around your pool.
Spray insecticide around the perimeter of your pool and lawn. Chlorpyrifos in liquid concentrate or a ready-to-use liquid form or diazinon as a liquid concentrate works effectively. Such insecticides are usually sprayed directly onto the ground; however, read your product's label for the manufacturer's instructions.
Sprinkle food-grade diatomaceous earth around your pool and yard. This fossilized algae breaks down a spider's skeletal system as it walks through its powder and causes it to die. Diatomaceous earth is a natural alternative for those who don't want to use insecticides near their home. You will need to reapply it after rainfall.
Avoid using lights around your pool, as they often attract spiders in search of prey. Remove any wood or compost piles near your pool; they are often hiding spots for spiders.