What type of coolant is recommended for the PipeWorx 400 cooler, and what happens if I use a different coolant?

Use only low-conductivity coolant part number 043810, which protects down to -37°F (-38°C) and resists algae growth. Do not use a conductive coolant. Using any coolant other than those recommended voids the warranty on all parts in contact with the coolant, including the pump and radiator. (Page 12)