The Salty Side: Saltwater Aquariums for Beginners

Saltwater Aquarium Heating

A reefer can not underestimate the importance of saltwater aquarium heating to coral, fish and invertebrates.  All reef inhabitants originate from warmer seas and in order to accommodate them we have to ensure their needs are met accordingly.

Unfortunately, heaters can (and do!) fail and I’m talking from experience.  Depending on the size of your tank, loss in temperature could happen over a few hours or within an hour and could prove catastrophic.  You may have left for work in the morning and come back to a failed heater and water several degrees colder than it should be.  

A heater’s thermostat could also fail resulting in much higher temperatures.  Higher temperatures are actually worse for a reef than cooler temperatures.  With cooler temperatures, processes that happen within coral slow down but the opposite occurs in higher temperatures.  The latter causing permanent damage that some coral may not recover from.

Luckily there are steps you can take to help minimise this risk, all of which I discuss in further detail below. 

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How to guard against heater failure


Always have two heaters working at the same time.  Should one stop working you will be covered.  Make a point of periodically feeling the heaters to see if they are emitting heat.


Use a heater controller, such as the one pictured below from Amazon.  A controller will include a probe which will constantly monitor the water temperature, and consequently maintain a constant temperature.

Without using a controller, you will be relying on each heater to individually maintain its own temperature setting.  Should either heater fail, the best case scenario could be a dead secondary heater.  However, the worst case scenario would be a broken thermostat.

A broken thermostat would cause the water to rise substantially in temperature and cook the contents of your aquarium.  A heater controller would detect the rise in temperature and shut the heater off at the correct temperature.


With the addition of a heating controller, you should be looking at heaters that are compatible with a controller.  These do not include any form of control on the heater itself.

Titanium heaters are the heater of choice for their durability and rapid heating capability.  

Recommended Titanium Heater:

Hygger Titanium Tube Submersible Pinpoint Aquarium Heater with Digital Thermostat & IC Temp Controller

What temperature should my saltwater tank be?

The temperature of a saltwater aquarium should be between 27.7 – 28.8 degrees Celcius or 82 – 84 degrees Farenheit.  Ron Shimek, a reknowned marine biologist from the US, has gathered data from more than 1000 reefs across the globe and found that this was the average temperature.

It certainly stands to reason that if marine fish and coral are living successfully in these temperatures that we too should keep our marine aquariums within this range.

So there you have it!

Heaters are one of the components of a saltwater aquarium that break down most often.  It is imperative to have two to, either one being a backup in case the other fails.

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