That's how it should work, sophia58. It will only stay on for a couple of minutes, then go off, and come back on a few minutes later. Check the aquarium's thermometer to see what the current temperature is in the tank. If it is at room temperature to start with (around 70-72 degrees), then it will take about 12-24 hours to bring it up to 78 degrees, depending on the size of the tank. It will NOT stay on all the time, as that would cause it to malfunction. It has to turn on and off every few minutes.
Date published: 2018-05-09