While there are many of fish will be fine with room temperature water in the fish tank, tropical fish and some other breeds need warmer temperatures. If the water gets too cool, tropical fish will die off. An aquarium heater is a simple way to keep the water at the right temperature and ensure that your fish are healthy and happy.
There are essentially two types of heaters to use. One is a separate apparatus that is set into the tank to gently warm the water. The other actually fits right into an aquarium filter, making it easy to clean and heat the water at the same time. Both are easy to use and will do the job required. There is another type of heater which lays under the gravel and you can also find heating mats that just sit underneath the fish tank. This type doesn't require much in the way of maintenance and can be the easiest option.
You will need to research the correct temperature for the fish you have. The heater will have a thermostat that can be set to the middle range of temperatures for the fish you are trying to raise. In large aquariums, you may need two or even three heaters to keep all the water at an even temperature.
It is important to check the functioning of your heaters from time to time since too hot water can be just as deadly to fish as water that is too cold. Use a separate thermometer to check the actual temperature every few weeks, just to make sure. It takes only a minute and can mean the difference between an aquarium full of dead fish and a fish tank full of happy ones. As long as you stay on top of the temperature of your tank, your tropical fish should thrive.