Oase FiltoSmart Thermo 100 - External Filter with HeaterFiltoSmart External Filter with Adjustable Heater The FiltoSmart 100 300 offers convenience and flexibility for medium sized aquariums. This external filter offers a powerful combination of mechanical and biological filtration for optimal clear and healthy water. The filter boasts many features such as an automated shut off so that no undesired water escapes while cleaning the filter, an EasyClick opening mechanism and an adjustable water flow rate on