Does Dawn Soap Really Kill Water Bugs in Pools?

How Water Bugs Work

• Water bugs typically have long, flat bodies and use wide stances to take advantage of the surface tension of the water and stay on top of water. They breathe oxygen, so they surface to breathe and search for food. They create tiny air bubbles as they dive, bringing air from the surface so they can stay under longer. They don't bite people, but they can arrive in your pool in such large numbers that they truly become pests.

How Dish Soap Helps

• Dawn dish soap, as well as other brands, change the surface tension of the water. It typically coats the surface, waiting for agitation to help the soap turn into bubbles; without agitation such as running water, the soap stays in its rather slimy original state, floating on top of the water. When the water bugs encounter the soap, they aren't able to skim the surface effectively because of the difference in the tension. Also, they can't create the air bubbles they need to dive free of the soap, so essentially they drown after contacting the dish soap. Bugs who come up from beneath the surface into the soap become covered in the dish liquid and can't breathe.

Adding the Soap

• Your skimmer and pump ensure there's water movement in your pool, so less soap is better. Too much can create a frothy mess. While this won't harm your pool, it may take a day or two to degrade so there are no more bubbles. Pour a small amount of Dawn dish liquid -- about 3 tablespoons -- near a light in your pool at nightfall. If you don't have lights installed, place a light near the pool's edge so it will be the brightest spot at night. The soap will spread out slightly, but it should still be concentrated enough to kill the bugs that migrate toward the light. If you notice more bugs the next morning, you can increase the dish soap amount to 1/4 cup for the next treatment, which you can add the next night if necessary. The soap is pH balanced and degrades quickly, so these small amounts won't harm your pool.

Scooping Out the Bugs

• Killing the bugs doesn't get them out of your pool, unfortunately. Especially if the water bugs arrived en masse at your pool, your skimmer may not be able to handle the load in a timely fashion. Instead, help your skimmer by using a small-mesh pool net to scoop out the dead bugs, which should all be floating at the top. Clean your skimmer the day after you apply the dish soap as well to ensure it doesn't become overloaded.