OASE HeatUp Adjustable Heaters maintain an even temperature level in aquariums. Choose the right size of heater, depending on the size of the aquarium. The adjustable heater is high-quality, easy to install and can be used in continuous operation. The activated indicator light lets you control the heating function with ease. The HeatUp adjustable heater is suitable for use in freshwater and saltwater aquariums. It can also be retrofitted with the BioMaster, BioPlus and FiltoSmart.