TropiCool heat pump chillers from Aquacal are a perfect solution for your chilling needs.  With the ability to cool water to temperatures as low as 45F, they can be used in climates all over the world for a huge variety of species. TC500 models require water flow of 20-45 GPM, and TC1000 models require water flow of 30-70 GPM. Operating cost ranges from 50-75c/hr, putting these among the lowest operation costs available.  All models feature Titanium heat exchangers to allow saltwater operation without risk of corrosion.