Heaters Rock pools accepted, marine environments have very little temperature fluctuation because their volume is so. This means that great heating is an essential for the successful marine aquarium. Here at tropical and Marine we stock a range of heaters you will always be able to rely on. You will indeed be able to fit and forget.
Thermometers Sadly, you can't rely on heater settings to tell you the temperature in your setup. In summer, the temperature in your aquarium can rise well beyond the set temperature and you need to be able to monitor the situation reliably using a good thermometer. A decent thermometer is the best early warning system you can have and ideally should be viewable from across the room for easy temperature confirmation.