50W heater in my 5.5 gallon tank isn't heating the water to 78 degrees, doesn't seem to get past 68. Am I doing something wrong or is it just defective? : r/Aquariums
No red light on Aquarium heater? | Heater Forum | FishLore Aquarium Forum
My Review of the Aqueon Pro Aquarium Heater (Tested!)
My Aqueon 7.5 Watt Heater Does Not Seem To Be Working. It Might Be Working,... | My Aquarium Club
Aqueon 50 W aquarium heaters - YouTube
Amazon.com: Aqueon Adjustable Pro Aquarium Heater, 50W : Pet Supplies
Preset Heaters | Aqueon
How to Troubleshoot an Aqueon Heater that not Working?
Aqueon Preset Aquarium Heater 50W – sjreef
How To Tell if Aquarium Heater is Broken? These Things Can Help!