Q: IW wrote,
My local fish store told me I didn’t need a heater for my betta tank. Is this true?
A: A betta tank should be warm and stable at an optimal temperature of about 78F (25.5C). A few wild species of bettas are naturally found in waters in the low 70s but the more common tank raised Betta splenden species prefer their water temperature between 76F (24.4C) and 81F (27.2C) When temperatures fall below 75F (23.8C) bettas tend to become much less active. Temperatures of 70F (21.1C) or below may prove dangerous to bettas.
Stability is equally as important as warmth. Large fluctuations from day to night can stress bettas leaving them susceptible to illness. Try not to allow your temperature to fluctuate more then 2 degrees Fahrenheit or 1 degree Celsius in a 24 hour period. An aquarium heater can help you to maintain a stable temperature. A lamp is not considered a stable source of heat and may cause greater and more hazardous fluctuations then no lamp at all.