You don’t have to learn the hard way... Heaters and Temperature Setup for a Reef Aquarium

Heaters have one of the unique positions in our hobby as being one of the most inexpensive and easy to install components of your tank’s life support system but is also the number one cause of equipment related failures. With that conundrum, it is all that more important to get it right the first time and arm yourself with the knowledge to avoid those mistakes.

Cobalt NeoTherm heater

Heater Selection

There are dozens of different heaters you could use and for the first year, there really isn’t going to be much of a performance difference between most of them. Use whatever heater you feel comfortable with. Set your budget and look to the customer reviews which are a great resource for something like this in which you have a ton of options that essentially do the same thing.

Eheim Jager Heater

The general target temperature for a reef tank is 78° Fahrenheit. For a 40-gallon tank, a 100 watt heater is sufficient in most scenarios where the ambient room temperature is kept at 70°F or higher. If your room temperature is typically below the standard 70° F than you will want to step up to the next 150-200 watt size heating element.

Bulk Reef Supply Heaters

We are using the BRS Titanium Aquarium Heater System for a few distinct reasons. We prefer titanium heating elements over plastic and glass just because titanium tends to be far more robust and compact. The BRS titanium elements are manufactured by a German company, Schego, and we partnered with them for a good reason - to create the best heater system in the industry!

BRS heater temperature controller

The remote controller is calibratable and allows for programmable on/off cycles. It has an easy to read digital display and a remote temperature probe that can easily be replaced by simply swapping it out with a new probe using the small 8mm headphone jack.

The last big feature is the BRS Heaters are the only option that has an audible alarm for most instances of failure. If a heater fails and gets stuck on or off, which will happen eventually, it’s not the kind of thing you notice just by looking at the tank until it is too late. An audible alarm changes the game in a majority of cases when you will be there to hear it or be there within a few hours.

BRS heater inside 40 breeder

Heater Installation

When you install the heater make sure to put it somewhere where it will always be submerged, even when the pumps are turned off for maintenance or feeding. Outside of water they can be a fire hazard and will quickly malfunction.

In our 40 breeder tank, we submersed the heater into the display as low as possible so that it would stay submerged even when doing a 10% water change.

BRS heater inside Red Sea E170

With the Red Sea E170, we put it in the back filter compartment. Choose the area that keeps a constant water level based on the baffling system to keep the heater submerged, this is critical with AIO aquariums because the baffling varies from tank to tank.

Heater Operation

To configure the controller, set it to display Fahrenheit with a target temperature of 78 degrees. The on/off cycle can be programmed as low as 0.3 degrees which is nice to keep the tank water temperature stable without a ton of fluctuation either way.


You can calibrate the BRS heaters for optimal performance using a high accuracy thermometer. You can also take multiple temperature readings using lower-cost thermometers and simply average the results for a fairly accurate temperature reading. Calibration is not required but is beneficial.

How To Avoid Heater Catastrophe

Throughout this series, there are a few information gems that dramatically change your success rates and this is one of them. Every electrical component on the tank is going to eventually wear out or break and you want to have a plan.

With a heater, the constant on/off cycling is tough on the electrical components and when a heater fails, it could be either in the ON or OFF position. This means it will either fail to heat the water or overheat the water, the latter being a bigger threat.

The best strategy to avoid that is just to replace inexpensive gear before it breaks. Meaning if you are using a $30 heater, throw it out as part of annual maintenance and replace it. Pick a date like January 1st and just do it every year.

BRS heater titanium heating element

If you are using something like the BRS heaters that use a higher quality long-lasting heating element coupled with an external controller. Simply replace the broken component which is most often going to be the controller. The controller and relays are what fail the fastest and cause the heater to stick in the ON position. In the event of a problem, check the temperature calibration and accuracy of the probe as well.

Neptune Systems Apex

As you mature in the hobby, you will learn about all sorts of different ways to deal with heater failures and catch them before they happen. Nearly 100% of experienced reefers would agree that replacing something before it breaks is a dramatically better option than attempting to catch it before it causes irreversible harm.

What’s Next?

The tanks are now heated and the next step is illuminating the tanks with high output lighting which will be your coral’s primary source of energy. Reef tank lighting is one of the hardest aspects to find clear and direct advice. Lucky for you, BRS is on your side and will give you the facts you need to succeed.

5 Minute Saltwater Aquarium Guide Episode #13

Looking for a different topic or have questions? You can binge the entire 5 Minute Saltwater Aquarium Guide playlist right here on our website. We also invite you to join the #askBRStv Facebook Group which is a free resource for you to ask questions, get advice, interact with other hobbyists and get your daily reef aquarium fix.

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