Do you have access to a constant temperature water source? If so, consider using a watersource heat excanger instead of a traditional heater or chiller. These systems can be used with wells, lakes, canals, oceans, or closed loop systems to heat or chill your culture water. With BTU ranges up to 213,000, you are able to heat and cool a significant volume of water. Min/Max flow rates are 30 and 70 GPM on either side of the system. Titanium heat exchangers are saltwater rated to prevent corrosion.