CoolWorks Microchiller. The MicroChiller provides a cooling solution for nano-reef tanks and other small aquariums that require cooler temperatures. The new MicroChiller not only solves the cooling problems inherent in nano-reef applications, but it also increases the flow of water in the tank that is necessary for the healthy growth of the coral. The MicroChiller uses solid-state heat pump technology, so there is no messy freon leaks or compressors that make irritating noises, which sets it apart from conventional chillers. Because the MicroChiller has so few moving parts, when used properly, it will provide trouble-free operation for many years. This compact chiller can chill bring down the temperature in a 10 gallon aquarium up to 4-6 degrees. Use in conjunction with the Porportional Thermoelectic Controller (sold seperately).