I bought a Winix air filter from CostCo for my apartment. I am amazed at how much 'material' is captured on the permanent pre-filter every two weeks. The pre-fi

I bought a Winix air filter from CostCo for my apartment. I am amazed at how much 'material' is captured on the permanent pre-filter every two weeks. The pre-filter needs to be rinsed every two weeks.