Lineba 500 Watt Submersible Aquarium Heater Anti-Explosion Fish Tank Auto Thermostat Protective Sleeve Suction Cup 53-93 Gallon

I have had this heater for several months and it has kept the water temperature stable at 77 degrees until today. When I got home from work I noticed the digital reader was flashing. My Oscar was on the bottom of the tank not looking very good. I checked the water temperature and it was 100 degrees. I quickly turned everything off and changed the water and used ice to cool it off. So far my Oscar looks like he will be okay and is swimming around again. Now I do not trust this heater. I want to send it back and get a refund but it is too late. I am very disappointed.

Update worked great for 3-1/2 months, until it shorted out. Nearly boiling all of my fish, I lost 1 fish due to stress. Not as good as I thought. ///___/// Works great in a 180 gallon stock tank in my garage, for my 12 Koi. I only keep the water at lowest temp setting on the heater and the water stays just above 55 degrees. Keeping them happy and hungry. Keep in mind I live in Michigan and the garage door is open a few hour s at a time. Temp outside is 30 right now, and the water is 55. I am circulating my water at 360 gallons an hour. I would recommend this heater, as a good investment. As of the others that had problems, as with most high manufactured products from overseas its hit or miss on the quality of some items.

I own a hot tub repair company.During the winter, we occasionally get calls from customers whose hot tub heaters fail. If we need to order parts, we use these heaters to prevent the tubs from freezing when the outdoor temperature is below 32 degrees.When turned to its highest setting, one heater will keep a 400 gallon hot tub between 50-60 degrees when it's 30 degrees outside. (the heater is made for a 100 gallon fishtank, so a hot tub is more water than it's designed to heat)I would never go into the hot tub with this heater in it, and I tell my customers the same, as it is a 120 volt electric device and it is not properly rated to protect a "swimmer" from electrocution.

The media could not be loaded.  Wish I could give this negative stars. After about 2/3 weeks the plastic casing melted while in my turtle tank. Do not purchase.

I purchased this item a year ago. In that year, the heater operated flawlessly. Then, almost a year to the day, I woke up one morning and checked my aquarium. Every single fish was dead. The heater had a flashing 'E' that would not stop. I don't have a very big aquarium, 60 gallons, but the fish I had were not something you buy at your local pet store. I scour the internet for fish from everywhere, including abroad. I was just beginning to breed some of them. I would bet that I had more than a thousand dollars in fish alone in the aquarium. I looked for a warranty but found none. I have since found a nationally known brand that offers a limited lifetime warranty. I am in the process of cycling my aquarium just to begin the process once again of scouring the internet for freshwater aquarium fish, something I had thought I would not have to do for a very long time. Would I buy this again? Probably not.

I purchased this heater in sept it seemed to work very well until yesterday when I kept hearing a popping noise coming from my aquarium that's when I noticed the plastic cover of the heater was melting I quickly removed the heater and unplugged it. I checked the heater I didn't find any cracks or other issues. Beware of this product it could cause electicuioion or at best the melting plastic could kill your fish

Used it over the winter for my ninja friends Mikey and Leo. They laid on it, pushed their rocks around it and on it, and it still works. Heats the water great. I’ve got it in a 200 gallon aluminum trough outside. The indicator light is on when it is heating, which was reassuring to be able to check it was working. On tank cleanup days I check the housing and rinse it out then check the glass tube for any damage. Make sure when you do it’s been off for a bit so the hot glass and cold water don’t inadvertently make it crack; it’s tempered and not supposed too but hey safety first.

I set this at 79 degrees in a 200 gallon tank, it rose to 88 overnight so I had to unplug. I contacted seller and they suggested laying horizontal in low water flow area so I did that and it and while still set to 79 degrees it rose to 84 before I unplugged. As I wrote before this is the first heater I have found that can heat this tank during cold weather to my desired 82 degrees, I just have to monitor and unplug each day and re-plug when I need heat.