This site offers some great tips about buying a submersible heater. A heater should be considered one of the most important peices of equipment in your tank and you shouldnot go for ’second best’ or on the cheap. If you think about it, any other peice of equipment, save the filter on a fresh water tank, can stop working, but your heater dying could kill your tank, especially in a colder room.
Alternately if your heater malfunctions and overheats…well I dont want to think about it.
Too often an aquarium heater is thought of as a simple and inexpensive device. An aquarium heater should be considered a critical piece of equipment, just like a filter that is essential to the livelihood of your tank inhabitants. One of the most efficient and popular types with aquarists are submersible, and here is our list of top pick units that have some of the best features one should look for when buying a heater for your aquarium.
One type that caught my eye was the fully submersible, virtually indestructable titanium alloy heaters (see the image in this article). these hearters, due to thier construction, are available in much higher watage than traditional heaters made of glass or plastic cases. They are available up to 800watts! Great for the larger aquariums. Often these heaters sport an external controller and some have an auto shut-off when exposed to air. Titanium is also resistant to corrosion and offers better heat conduction for better control.
