Yes, bristlenose plecos need a heater in their tank. They are tropical fish, so they need warm and stable temperatures of around 74°F to 80°F (23°C to 26.5°C) to thrive. Water that’s too cold can lead to growth stunts, stress, illnesses, and even death.
Even if your bristlenose pleco’s tank is located in a warm area, the water temperature can still fluctuate. So, you need to install a heater to ensure your bristlenose plecos live long and healthy lives.
It’s recommended to get adjustable heaters with a built-in thermometer. That way, you can maintain the tank’s temperature easily. Also, since bristlenose plecos’ tank is usually quite large, make sure your heater is powerful enough to warm up the entire tank.