GAME 4513 SolarPro XD2 - Solar Heater for Above Ground Pools Heat your pool water the GREEN way using free energy from the sun!. Designed for any size above ground pool - no additional adaptors necessary. On average increases the pool water 10 degrees in 3-8 days depending on the size of the pool. Easy to install - no gas or electricity needed. Space saving and aesthetically pleasing when compared to solar panels. Pump is required to circulate water (sold separately) If pump is 1 HP or higher, a Bypass Kit is required (sold separately)