In reef keeping stability is king. The aquarium heater is one of the pieces of equipment that helps keep the temperature of the tank stable. Most aquarium heaters work by taking electricity and converting it into heat. That heat is then transferred to the water around the heater and circulated throughout the tank through normal flow. When the heater senses a set temperature it shuts itself off.
Life inside the tank requires a stable temperature for success. If the temperature slips too cold fish can become lethargic and if too cold will perish. One of the most common catastrophic tank killers is a malfunctioning heater particularly when it gets stuck in the on mode and overheats the tank. Too hot of an environment and catastrophic death happens very quickly. For this reason, I only run heaters with additional temperature sensing and heater control such as through a Neptune Apex controller that will shut off power to the heater at a set temperature range. A good heater will hold temps to the right set of degrees, be reliable in turning on and off, and fit where I want the heater to be placed. Here are some of the heaters that have worked well for me in that I recommend.
Eheim Jager TruTemp Aquarium Heater
Situation: I currently use Eheim Jager TruTemp Aquarium Heaters on my 75-gallon reef tank and 210-gallon reef tank. I use two 75 watt heaters on the 75 and one 300 watts on the 210.
Heaters are critical in providing a stable temperature for the tank inhabitants and need to be reliable as a malfunctioning heater can cause a critical issue in the tank quickly.
Background: Eheim Jager heaters have been around the hobby for a long time and operate as a heating rod that heats water around it. There are many sizes to the heater ranging from 25-300 watts with a physical size increase as the watts go up. The heaters are glass and are required to be fully or nearly fully submerged. The heaters are held to glass/acrylic with the use of suction cups. The heaters do have an automatic shut-off if the heater is dry.
Assessment: I have not had any issues with these heaters. They are well constructed and hold the tank temperature very well. With that said I don’t think I would trust any heater as a malfunction specifically in the always-on function can kill off a tank quickly. I have always run these heaters and any other heaters with a controller that monitors temperature and shuts the outlet off when out of range. These heaters sit in my sump.
Recommendation: Good quality, good at holding temperature, and is usually priced very competitively. When these go on sale you can get them at an excellent price. I would recommend these heaters, but only if the temperature is monitored and power to the heater is automatically shut off when out of range.
EHEIM Jager Aquarium Thermostat Heater
All 9 EHEIM Heater models are 100% fully submersible and come with a new TruTemp dial that allows the user to recalibrate the heater within a +/- 0.5F degree accurancy for precise temperature readings.
