Aside from the condition of the water there is probably nothing as important to properly maintaining a fish tank then keeping the temperature of the water at a set level. Both salt water and fresh water fish thrive best in warm water that stays constant. They are after all tropical fish. Gold fish on the other hand are cold water fish and can handle fluctuation in temperature.

The temperature of the water is important for the health and welfare of your fish. If the temperature drops by one degree over a twenty four hour period it can leave many fish susceptible to diseases such as "Ick". If not caught soon enough it can create irreversible damage and kill any and all the fish in a tank. This is why it is doubly important to keep a close eye on the water temperature during the change of season, particularly as winter approaches and temperatures drop.

There are a variety of different fish tank heaters on the market and depending on how much you are willing to spend will determine how functional the one you get may be. The cheaper ones may save you money but they are more likely to break or malfunction, thereby endangering the investment you have made in your fish. Many times the cheap heaters also do not have an accurate heat setting, which makes dialing in the temperature difficult.

For most people a mid priced heater will do the job they are looking for. Their thermostat controls are reliable and they maintain a constant temperature without having to make adjustments all the time. It is important to check your fish tank heater periodically to make sure it is operating correctly and after about a year of use there is a good chance that it may need to be replaced.

The best way to make sure your fish tank heater is working properly is to invest in a thermometer. These days you can purchase thermometers that stick to the outside glass of the fish tank. This makes it easy to monitor the temperature because it is always in a conspicuous spot. You can use the type that float around inside the fish tank but they are not always as easy to read and more often then not they float behind a filter or some other obstruction making it impossible to see what the temperature is.

Once you have your heater it is best to place it near a filter. This allows the heated water to be distributed throughout the tank keeping hot and cold spots to a minimum. A heater is an important part of any fish tank ecosystem and by keeping the water temperature at a constant level your fish will be disease free and entertain you for many years.