How to Keep Wolf Spiders Out of a Pool

Making Changes to Your Pool

Clean your pool weekly so it doesn’t attract any pests. Start by skimming the water with a net to get rid of large debris, such as leaves, sticks, and other organic material. Then use a pool vacuum to clear out any smaller particulate like sand and dirt that may have sunk to the bottom. If you notice any green algae or mold stains around the edges of your pool, wet a stiff-bristled brush with clean water and scrub at the stain in circular motions to break it apart. If it’s persistent, try putting 1 tbsp (14 g) of baking soda on the brush and scrubbing it again. You can also buy an automatic pool cleaner to reduce your maintenance, but you’ll still need to remove large debris on your own. If your pool has a filter, run it as often as you can throughout the day so the water cycles and stays fresh between cleanings.

Use a surface tension reducer so spiders can’t float on the water. Surface tension reducer is a chemical that causes small pests and items to sink rather than float. Purchase a bottle of surface tension reducer online or at a pool supply store. Follow the directions carefully on the bottle and squeeze the formula into your pool. Once a spider falls in the water, it will sink and be sucked up by the filter or your pool vacuum when you clean.

Cover your pool when you aren’t using it. Check the measurements of your pool so you can find a pool cover with similar dimensions. Whenever you aren’t swimming or enjoying your pool, roll the cover over the water and pull it tight to the edges. The cover prevents anything from getting into the water so wolf spiders and other pests that attract them can’t reach the water. Your pool cover will vary in price depending on the size and material. You can buy them online or from pool supply stores. Pool covers also help reduce energy costs from heating your pool.

Adjust your pool’s pH and alkalinity to kill sources of food. Your pool’s chemical balance helps reduce algae growth, which is the main thing that attracts water bugs and spiders. Get a pH and alkalinity kit online or from a pool specialty store. Dip the test strips from the kit in your pool’s water and wait for the color to change to find your measurements. If the pH is between 7.4–7.6 and the alkalinity is between 100–150 ppm, then the chemicals are balanced. If not, then use balancing chemicals to bring your pool within the range. For high pH and alkalinity, you can use muriatic acid to lower it to the correct levels. If your pool has low pH or alkalinity, you can use borax. The amount of product you add to your pool depends on the volume of your pool. Aim to test your pool water once or twice a week to ensure it stays within the acceptable range.

Deterring and Killing Wolf Spiders

Clear plants and clutter from your pool area to get rid of hiding spots. Wolf spiders tend to stay close to the ground and live in dark hiding places, such as plants, firewood, and outdoor cabinets. Move all of the items that you can away from your pool and store them somewhere else in your yard. If you have plants next to your pool, consider digging them up and replanting them somewhere else so spiders are less likely to get into the water. Wear gloves when you’re handling your items in case there are any wolf spiders on them. While they aren’t venomous to humans, their bite can still really hurt.

Try planting peppermint in your yard as a deterrent for spiders. Look for fresh peppermint plants at your local nursery or purchase seeds online. Place the peppermint near the perimeter of your pool to keep the wolf spiders away. The strong odor and oils from the plant are unpleasant to spiders, so they will avoid the area. You can also try using chestnuts or lavender to deter spiders, though they may not be as effective. If you can’t put physical plants in your space, you can also try applying peppermint, chestnut, or lemon essential oil around your pool as well.

Limit your use of outdoor lights so you don’t attract prey insects. Pests love bright outdoor lights at night, which may attract them to your pool. In turn, those insects may draw wolf spiders closer to your pool and home. Leave the lights turned off as often as you can to help eliminate the spider’s food source. If you do need to leave lights on, position them away from your pool and other structures. That way, the pests will be drawn toward the light and not the pool. Try switching to yellow-colored or sodium vapor bulbs since they don’t attract as many insects.

Sprinkle diatomaceous earth around your pool for a natural pesticide. Diatomaceous earth (DE) has a flour-like consistency and leaves small cuts on a wolf spider’s body after coming into contact with it. Sprinkle the DE around the edges of your pool and any areas where you want to keep spiders away. If it rains or the DE rinses away from your pool area, be sure to reapply another layer so it stays effective. You can buy diatomaceous earth from gardening supply stores or online. Do not use diatomaceous earth that’s made for pool filters since it has a different formulation and won’t be effective for pest control.

Place traps around your pool area to catch and kill the spiders. Spider traps have an adhesive surface that spiders stick to when they walk through them. Get a pack of commercial spider traps online or from a local yard-care store and place them around your pool area. Keep the traps near dark corners or along the edge of your pool so spiders are more likely to get caught inside. Once the traps are full, simply throw them out. Spider traps will also trap any other insects that get inside, so check them regularly to make sure they aren’t full. Avoid placing spider traps where young children or pets can access them.

Have your yard treated with a commercial pesticide for a large infestation. Hire a professional pest control service to deal with the wolf spiders if you’re unable to control them any other way. The service will use a chemical spray around your pool and the affected areas to kill the spiders on contact and create a protective barrier in your yard. If you want to keep spiders out long-term, reapply pesticides every 2–3 months. Pesticides may also kill beneficial insects in your yard. You may be able to use store-bought pesticides, though they won’t be as strong as what professionals use. Many spiders will only die if they’re sprayed directly with pesticides, but they won’t be as affected by residual pesticide on the ground.