It can be very unpleasant to find bugs in your pool, especially if they are hazardous or harmful. Unfortunately, even a crystal clear pool with good chlorine levels can be home to water bugs, so let’s learn more about water bugs in a pool and how to get rid of them.
What are Water Bugs?
Two water bugs are the primary culprits in swimming pools. Since they are both members of the Corixidae family, they can look very similar, but they have different behaviors and require different treatment methods. Here are the water bugs you are most likely to encounter.
A water boatman has a flat, boat-shaped body and long hind legs. They are usually about a half-inch in length. They eat algae and underwater microorganisms and can also mosquito larvae and other pests. They lay their eggs in algae underwater.
Despite spending so much time in the water, these insects breathe air, and they can also fly. Water boatmen are harmless and can even be considered beneficial when they eat unwanted organisms and larvae.
Backswimmers look like water boatmen and are the same size but have more slender bodies than oval-shaped ones. The easiest way to distinguish them is the feature they are named for – backswimmers swim upside down, using their long hind legs to propel them through the water.
Water boatmen swim right side up. Backswimmers are predators, and in natural water, may live by hunting small fish or tadpoles. In a swimming pool, they usually prey on water boatmen. Backswimmers will attack humans and have a painful bite, similar to a bee sting.
Like a bee sting, the bite is usually painful but not dangerous, but some individuals may be more sensitive to the bite.
While the water boatman is harmless and even beneficial, large numbers tend to attract the unpleasant backswimmers. Both of these species of insects lay their eggs in algae and require air to breathe. In addition, these water bugs can fly and walk and swim, which makes it easy for them to find their way into almost any pool. So how do you get them out?
Are Water Bugs Harmful in a Pool?
The presence of water bugs is undesirable in a pool. While water boatmen are not harmful insects, their presence indicates algae and other microorganisms living in the water. And large numbers of water boatmen attract backswimmers, who have a painful bite. So most of the time, it’s a good idea to get rid of water bugs in a pool.
How to Get Rid of Water Bugs in a Pool
If you have just a few water bugs, the easiest way to kill them is this:
- Turn off exterior lights and pool lights.
- Aim a spotlight down into the water at the deep end of the pool.
- Gently add 2-3 teaspoons of liquid dish soap to the water’s surface within the circle of the spotlight.
- Water bugs breathe air, so they will surface to breathe and be attracted to the light. The surface tension of the soap will not allow them to breathe, and they will drown.
- Skim the bodies from the pool the following day.
- Follow up with cleaning and balancing your pool to remove and prevent algae that attract the water bugs.
To get rid of bigger water bug problems in your pool, follow these steps:
- Skim the pool. Using a net skimmer, remove as many bugs from the pool as possible. Because these bugs can walk and fly, move them well away from the water, or they may end up right back in your pool after skimming.
- Scrub the pool. Using a scrubbing brush, scrub the walls of the pool to loosen and remove algae and debris. Remember to scrub walls, steps, and ladders.
- Vacuum the pool. Use a pool vacuum to remove any remaining bugs, along with as much debris and waste as possible.
- Test your pH and alkalinity and adjust if necessary. Test your water’s pH and total alkalinity, making sure the pH is between 7.4-7.6, and the total alkalinity is between 120-150ppm. Treat the water if necessary, and test again after 3-4 hours of allowing the filter to run.
- Shock the pool. Use a pool shock to shock the pool.
- Balance water chemistry. About 24 hours after shocking the pool, test the water and make sure that chlorine, pH, and total alkalinity are in the correct ranges.
- Vacuum again. If you have had a severe water bug problem, vacuum the pool again after shocking to remove any organic matter that may have been killed by the shock, and make sure that there are no food sources for water bugs.
Following these steps to get rid of water bugs in your pool. But how do you keep them from coming back?
How to Keep Water Bugs Out of a Pool
The truth is, shocking your pool doesn’t kill water bugs. Instead, it kills algae, which can attract water bugs. To keep water bugs out of a pool, consider these factors.
Algae and Pool Vegetation
Water boatmen eat algae and microorganisms, but algae, water plants, and even vegetation close to pool water can attract insects. So keep your pool clean and control algae growth.
Also, note whether you have plants and vegetation near the pool, or plants, vines, or tree branches overhanging it. Lush, plant-rich landscaping around a pool looks beautiful but can also attract water bugs and other insects.
Outdoor and Pool Lights
Water boatmen and backswimmers are attracted to light, and so are many other insects. Outdoor lighting and pool lights can be a cause of insects in a pool. Turn off your pool lights at night, and keep outdoor lighting several feet away from pool water. To reduce water bugs:
- Keep outdoor lights at least 30 feet away from pool water
- Use the smallest number and lowest wattage lights as possible for your needs
- Yellow LED or sodium lights attract fewer insects than mercury, or white LED fluorescent or incandescent lights
Keep the Pool Clean
A clean pool with balanced water and good chemistry will be a less attractive habitat for water bugs. Maintaining water quality and regular skimming will reduce the presence of water bugs. Consider covering the pool when it isn’t in use to prevent bugs.
Nearby Natural Water
Water bugs live in natural swampy, muddy waters. If your pool is near large puddles or muddy areas, they can host water bugs that may migrate to your pool or be washed into your pool by heavy rains. If you have nearby natural water, particularly if it’s still water, you may have more problems with water bugs.
To keep water bugs out of your pool, pay attention to the pool surroundings and environment, and keep the pool clean and balanced. Some other methods to consider include:
- Use an algaecide. In most cases, keeping the pool clean and monitoring the water quality will manage any algae problems. However, in some cases, you may want to consider using an algaecide to make your pool less hospitable to water bugs
- Spray with soapy water. Fill a spray bottle with liquid dish soap and water solution and keep it near the pool. Use it to spray insects when you see them kill them, and then remove them from the pool
- Use Borax around a pool deck. Borax can help deter insects from crawling into a pool, although it does not deter flying insects. However, if you have a yard or landscape with many insects, creating a barrier with Borax can help reduce the number of bugs in the pool.
Water bugs can make a pool unappealing for swimming and can also lead to painful bites. Because these insects are versatile and resourceful, it can be challenging to keep them out of a pool.
Keeping your pool free of the algae that water boatmen and backswimmers need, reducing or eliminating light near the pool, and keeping the pool covered are the best ways to make sure that you don’t develop a serious water bug problem.
For the occasional bug, regular skimming and a spray bottle of soapy water will handle the situation. Learning more about your specific pest insects, what they eat, and how they live will help you reduce water bugs and keep your pool a happy, healthy, clean place for swimming and relaxing.