Pool chlorine tends to deactivate most pesticides. However, fish and other aquatic life are very sensitive to pesticides. This is why we do not treat backyard ponds. We take a different approach. Mosquitos tend to lay eggs within moist, hard-to-reach pockets and crevices. This is why we allow the adult mosquitos to contaminate themselves within our In2Care Mosquito Trap and spread mosquito-killing powder to any hidden site where they attempt to lay eggs. This allows homeowners to reduce their mosquito population without affecting their pond or pool.