A reader told us that he often finds a lot of worms in his swimming pool after heavy rain. He thinks they live in the shallow channel drain which surrounds the pool. When it rains, they look to escape this drain, and end up in the pool. He wishes to find a way to remove the worms, as it is a pain to have to vacuum the pool to remove them every time it rains.

The worms our reader keeps having to remove from his pool are earthworms. We hear about readers finding earthworms in large numbers and surprising places after it rains, like their patios and driveways. Earthworms live underground in moist soil where they are protected from the sun, which can dry them out and paralyze them. When it rains, the wetness allows the worms to safely move to a new location. Earthworms breathe through their skin, and it must stay wet in order for oxygen to pass through to them. Also, they can live under water for weeks as long as the water has sufficient oxygen in it.

So, how can our reader get these earthworms out of his pool? Well, first he should know that these worms aren’t harmful to humans, and are extremley beneficial to the environment.  They might be living in the drains, but they also might be living in nearby soil and moving to the pool when it is safe for them to migrate. Once they are in the pool, they are stuck and there is now way for them to get out. There is no easy solution to get rid of these worms, but there are some options that will help prevent earthworms from swimming in his pool. He can invest in a pool cover. If the worms are living in soil and moving to the pool when it rains, this will prevent them from entering it. He can also add crushed limestone to where the concrete around his pool meets the soil. The limestone will raise the pH of the soil around the area, which the worms don’t like and will stay away from.

In summary, one of our readers wants to stop earthworms from swimming in his pool after rain storms. We recommend he use crushed limestone around his pool or invest in a pool cover!