Review on 🐠 Penn-Plax 75-Watt Fully Submersible Aquarium Heater: Precise 1 Degree Accuracy - Ideal for Up to 15 Gallon Tanks by Jessica Brown

I had a newer "digital" temp which has an adjustment, "click button" on the cord, closer to the plug than the heater. I really liked them, but they lasted a year at most. So I went back to the old glass tube style. I have 150 watts and it's a bit high on the back glass. I have 29l. Tall tank so I can just set mine up and I don't even have to turn it off for a water change and still not go below the 'red line' i.e. 'turn off when the water is below the red line'. If you have a working aquarium with glass algae, be sure to clean it very clean. I did and so far the suction cups are holding up well and firmly.