GarfieldDC
Regular
I really don't think you need to heat the water. I've had a big aquarium in the house for years now and never had a heating element in the water. The only time I needed to heat an aquarium was when I had turtles. I used a table lamp with a bulb at the time as they need heat to digest their food. The only thing that will kill the fish quickly is dirty water. Just ensure the water is clean and clear and you don't overfeed them. They should be fine. I would suggest you avoid using tap water as the chlorine in the fish don't like the chlorine in the water.