How to maintain a constant temperature in a saltwater aquarium

Table of Contents

To maintain the proper temperature in a saltwater aquarium, specialized equipment is necessary. In this article, I provide a brief description of these devices and discuss how they work.

Heating the water in the aquarium

Heaters with thermostat

Using heaters with built-in thermostats allows for the maintenance of a constant water temperature in the aquarium. This is crucial for providing a stable living environment for marine organisms. The thermostat in the heater allows for setting a dedicated temperature and controls the heater to maintain the temperature at the set value.

Heaters without thermostat

These are simpler devices that require an external temperature controller. If we use some automatic temperature control device, a heater without a thermostat works well.

Heating mats

Less commonly used in practice. Often placed under the sump’s bottom, heating mats evenly distribute heat.

Cooling the water in the aquarium


These are specialized devices used to lower the water temperature in the aquarium. They are essential in larger aquarium systems or where the ambient temperature may lead to water overheating. Chillers are integrated into the water circulation, usually with an additional circulation pump.


A simpler and more economical solution for cooling the aquarium, especially useful in warm months. Fans increase water evaporation, which effectively lowers its temperature. They should be aimed at the aquarium water surface.

Automation of the cooling area

Thermo control devices, like those offered by Reef Factory, allow not only for monitoring the temperature through a phone app but also for managing heating and cooling systems. Once properly programmed, the device can automatically regulate the temperature, which eliminates the need for constant checking of the aquarium’s conditions. The alert feature informs users when the temperature goes beyond safe limits, preventing the risk of marine organisms dying.


Thanks to modern technology, maintaining optimal temperature in a saltwater aquarium is easier than ever. Automatic temperature management systems provide peace of mind and comfort to aquarium owners, allowing them to focus on other aspects of care and spend more time admiring their underwater world.

About the author

Picture of Marek Protasewicz

Marek Protasewicz

Reefkeeping has been my passion for over 10 years now. I love learning. The hobby has taught me many valuable lessons, patience being the best example. Combining work and passion is my path. I run Crazy Coral, a marine aquarium shop, for a number of years. Building this business from the scratch I learnt from my own mistakes at a heavy cost.
Later I managed a project aimed at development of methods for quick growth of Corals in non-natural conditions. The project was carried out by Get Sales, Poland. Presently, I am responsible for distribution strategy at Reef Factory, of which I am a co-founder. The company produces smart devices for marine aquaristics. The last projects I have been involved in are Social Reef and ReefPedia.

My social media profiles

Logo Social ReefLogo instagramFacebook marek protasewicz     youtube marek protasewicz