The skimmer basket is designed for catching the debris from your pond and housing the pump.
In the autumn season, if your pond is built around the trees, you may check out the skimmer basket at least twice a week. If the leaves block the entrance of basket, the pump may not have sufficient water to circulate. You may hear the pump sucking air or see some air bubbles coming out from your bog filtration pond. This is an indication that you need to clean the skimmer basket immediately otherwise pump may get damaged very soon and the warranty will be void.