Use this map to determine which level of freeze protection you need.
Areas 10 & 11 are safe with the included "Dole Valve" protection
Area 9b should have the optional Recirculation Freeze protection.
Area 9a and colder should have a closed loop system (Our system 5).
Florida Planting Zones http://www.wgcu.org/fllandscape/zonemap.html — WGCU Public Media - Fort Myers, FLPlanting Zone map of North America www.usna.usda.gov/Hardzone/ushzmap.html