The CoolWorks IceProbe Small Aquarium Chiller (IPAC-50W) is the perfect cooling solution for small aquariums (such as nano-reef tanks). This is a unique chiller that has a cooling element that connects to siphon overflows, pre-filters, sumps, or aquarium walls, or can be suspended with a bracket or lid over the top of the aquarium (not for in-line use).NOTE: While the controller is not required, it is the only way to control the temperature (otherwise the IceProbe is always on). We offer the Model TEC65 for the range from 65ºF to 85ºF and the Model TEC45 for the range from 50ºF to 65ºF.Features:Diagram showing how IceProbe connects to aquarium or sump. 50 watts cooling powerEasy bulkhead installationQuiet, efficient & reliable Comes with power converterMore Info from CoolWorks Web site(new window)Typical temperature pull-downs:10 gallons: 6-8 degrees20 gallons: 3-4 degress40 gallons: 1-2 degrees