Most experienced saltwater aquarists know that using an inexpensive, poorly constructed tank heater can quickly lead to a disaster by either allowing the tank to chill, or worse yet, over heat. Not only will a heater that fails to turn off "cook" your tank critters, it can also cause an electrical fire in your home. Poorly constructed heaters are more likely to fail and can also create a stray voltage leak in your tank.
Stray voltage (small amounts of electricity entering your aquarium water) can have subtle effects (fish acting strangely) in you tank, or very dramatic ones (fish and inverts dying). Knowing what features to look for in a heater can protect you and your wet pet friends.
We strongly recommend that you read customer reviews on the aquarium heaters that you are considering buying before you purchase one. In the past there have been aquarium heaters on the market which are manufactured and distributed by companies with very good reputations which have failed during use. One such company's new line of heaters had a number of catastrophic failures. The heaters would fail to turn off when the proper tank temperature was reached, overheating the tank water and killing everything in the tank. The manufacturer was very good about covering the fish and livestock losses due to these heater failures, paying the customers the replacement cost of their losses.
The lesson here is to purchase your aquarium equipment, especially an aquarium heater from a manufacturer with a good reputation. You might pay a bit more, but it could cost you less in the long run.
About Submersible Heaters
Most saltwater aquarists have found that the submersible type heaters work best in their aquariums because they require little attention, particularly if the aquarium water level becomes rather low.
Aquarium heaters which are not rated as submersible can short circuit and fail if they do happen to fall into the tank. Read our top pick aquarium heater reviews and compare prices on units that are considered to be of excellent quality and have been highly rated by users.
About Hang-On-Tank Heaters
Many saltwater aquarists prefer the non-submersible hang-on-tank type heaters. While some of these models are complete with a built in hanger, others require a separate hanger, still others use rubber or soft plastic to hold the heater on the side of the tank. . Most of the hang-on-tank aquarium heaters require constant submersion in water. If the water level drops too low in the aquarium, the heater becomes exposed and can then over heat and burn out. The good news, here are some models that have low water level protection or indicators, or that automatically shut off when over heating occurs.
About Cable Heaters
Installed underneath the substrate and manipulated by an additionally needed electronic controlling unit, cable heaters are common in freshwater planted aquariums to eliminate reduction areas (dead spots) by convection, but are seldom used in saltwater tanks.
Most frequently, cable heaters are used in reptile and amphibian enclosures, rather than using infrared heat lamps. Pros - can't be seen; allows the substrate to retain and generate an even distribution of heat. Cons - difficult to replace because the substrate has to be removed to get to it; might be OK for fish-only but not recommended in reef tanks. If you have a cable heater in a reef tank and it needs to be replaced, you would, in all likelihood, end up having to destroy all of you aquascaping and moving your corals. Cable heaters are available in a variety of lengths and wattage.
Other Heaters & Accessories
Compare prices on more submersible and hang-on-tank aquarium heaters, as well as suction cups, guards, holders, and many other heater accessories and replacement parts.