Dimensioning a solar swimming pool heating includes many factors:
Length of the bathing season
Average regional temperatures
Desired temperature of the pool
Site solar resources
Collector orientation and tilt
Use a pool cover.
Solar contractor use worksheets and computer programs, to determine system requirements and collector sizes.
Basically, the surface of your solar system equal to 50% should be - 100% of the area of your pool. In cooler and dimmer areas, you can the relationship between the collectors and the pool to increase surface. Add collector square film also extends the swimming season.
For example, a 15-by-30-foot pool in Florida requires usually a collector which is equal to year-round use to accommodate 100% of the pools square metres. This is equivalent to 450 square meters of collectors. In Northern California, most people of outdoor swimming pools use 6-8 months per year, so they typically estimate their systems at 60% - 70% of the pool surface.
In any climate, you can usually drop the required collector area with a pool cover.
You want a properly dimensioned pool pump for a solar system. If you instead of a traditional pool heating with a solar system, you may need a pump bigger than your current or a separate, smaller pump of the pool water and by the collectors to move.