Start by taking out the chemicals, which should be replaced at least a week before you close your pool. If you need to buy a new cover, do it now. You can also buy a phosphate remover to prevent algae growth, which can be a real pain in the ass in the summer. Before closing the pool, check the temperature regularly to make sure the water is 65 degrees or below. If you close your pool too soon, you may end up with a green, unhealthy swimming environment.
- Ian A. Johnson, Small Business Owner