To give you the short answer, yes, betta fish need a heater. Betta fish need to be kept at about 76 to 82 degrees Fahrenheit to maintain good health. That means most of us will have to use a heater in our betta tanks. The only time it makes sense to not heat your betta's bowl is if you live in a very warm area where it never gets much colder than 60 degrees, even in the middle of the night. The other instance is if you keep your betta in a very warm room that stays warm all the time. Remember, bettas need stable temperatures -- even a 10 degree drop in their water temperature over a twelve hour period is really not good for them.

So if bettas need a heater, why are so many betta bowls out there heaterless? Because most people do not properly care for their betta fish, and that is why so many bettas only live a few months once you bring them home. It does not have to be this way! Your betta should live two or more years in your care at the very least. Keeping them warm is one of the best ways to ensure this happens. The other three ways are to put them in a properly sized bowl (2 gallons or more), change their …show more content…
There are a lot of options. If you have a standard, flat sided tank, you may want to get a traditional tube-shaped filter. These are anywhere from six inches to 18 inches long (the 18 inchers are for huge tanks of 100 gallons or more). In the old days, tube heaters had glass outsides, and some of them still do, but it is much better to buy a tube heater with a metal or a rubber/plastic exterior. These materials are much safer than glass because they will not break or shatter if you drop the heater, and also because extreme heat differences will not shatter metal or plastic, but they can shatter glass. Always make sure your betta heater is covered by enough water... letting the water fall below a certain point will damage your heater and also create a fire