The Cobalt Aquatics Mini-Therm Submersible Aquarium Heater is designed specifically for smaller tanks and terrariums. Featuring a compact and fully submersible design, this heater has an internal ceramic radiator that provides even heat distribution for reliable use. It will raise the aquarium’s recommended temps by up to 10 degrees above ambient temperature, with a constant “on” design that keeps everything running smoothly. The shatterproof casing is built to withstand accidental damage—or aggressive turtles—so that you can count on keeping your tank just as it should be.
Mini, fully submersible aquarium heater is good for smaller freshwater tanks, marine tanks, and terrariums.
Compact design features a thermal-plastic polymer that is shatterproof against accidental damage or turtles.
Constant “on” design provides reliable use to keep your tank at a stable temperature.
The internal ceramic heat radiator proves the most even and best heat distribution from the heating elements.
Will raise the recommended size aquarium temps by up to 10 degrees above ambient temperature.
It arrived in a crushed box under a bag of horse feed. A Stays at ambient 70 F. Does not work.
Awesome for the price!
on Mar 18, 2020
I've had this one over a year and it hasn't failed yet. The temperature stays ideal at just under 80°, I love it and recommend for smaller setups.
on Oct 28, 2019
Received it, put in water against side & next day, water wasn’t getting any warmer, so I felt it & there was no warmth.
Cobalt Aquatics 5 W
on Apr 11, 2019
I bought 3 of these heaters. 1 worked well (heated tank to about 78 degrees), 1 kept my tank at only 72 degrees and the third one didn't work at all. All 3 tanks are 1 gallon with the same room temperatures of 70 degrees. Very disappointed with this purchase.
Item doesn't work
on Nov 27, 2018
I bought 2 of these heaters and i am highly disappointed. I don't like how there isn't a way to tell weather it is working unless you feel the tank. I had to keep unplugging and plugging the heater in for it to work right. I was worried at first because in the instructions it warns that there isn't a thermostat within the heater so it won't shut off. But after having them for the first month i wasn't worried anymore because the heaters don't work. I will not be ordering anymore of the cobalt products.
on Nov 30, 2018
Great product. The first one to arrive didn't work at all. I notified Chewy customer service, they sent me another one and it works just amazingly. I have a beta fish and they need to stay in at least 75°F water, I couldn't get my house to that temp. without dying from heat exhaust so this product definitely helps, BIG TIME.
Simply Not Good
on Oct 28, 2018
I bought this for a Betta tank that is 3 gal in size.
It plainly isn't enough for such a tank, even though the manufacturer claims it is. There is no indicator light on this either so you have to guess if it is working or not. Please be aware there is no thermostat either. I put this in a 16 ounce cup and it wouldn't even heat that.
Too Much Heat
on Oct 28, 2018
It's a great working heater, but I have found that it produces much more heat than needed.
Good heater for smaller aquariums
on Nov 12, 2018
Good for what i needed. It's not adjustable though.
Item did not work
on Sep 17, 2018
I requested a replacement. If the next one works I will change my review.