If you are using a heater, a solar blanket is a must-have item, as you can lose 50% or more of the heat gained overnight due to the heat transfer into the cold air. Also, about 75% of a swimming pool's heat loss is due to evaporation. A solar cover minimizes heat loss from evaporation by acting as a barrier between swimming pool water and the air. Another must-have for any pool is to have a sump pump. They are super important since they prevent all kinds of possible issues. I hired a group of professionals to build a pool in my backyard this summer, and they got the sump pump from sumppumpadvisor.com.