HAPPY ENDING!! Watch the update:

A cobalt aquatics neo-therm heater blew up in my aquarium sump and killed my fish. Specifically, my freshwater stingrays.

TO CLARIFY: This was not an electrical issue. There was no short. A GFCI or any other safety precaution would NOT have prevented this.(Even though the heater WAS plugged into a GFCI outlet).
To elaborate on what happened with the heater: There is a wire that is coiled inside the heater. The heater is filled with a resin. In this faulty heater, the resin was not evenly distributed, allowing for the wire to heat unevenly creating hot spots within the heater. This caused the resin to heat and expand, blowing the end of the heater apart and leaking out the toxic resin into the aquarium. The heater continued to function and no voltage was leaked into the aquarium. The resin in the water is what killed the fish. Nothing else.

Whats next? Here is the update:

I also did an hour long podcast on this story. What led up to this event:

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What do you think?


Written by The king of DIY

Content AuthorYears Of Membership


  1. Im sorry to have to share this story with you. Im also sorry it took me so long. I hope you can understand that I simply needed time alone to reflect on my hobby and mourn for these animals. If I had told it sooner, it would have been told in a drastically different way. I feel good about this video and am glad I got it out. Later today, I have a podcast coming out that will elaborate on this story. It is an hour long.

  2. That’s insanely irresponsible for Cobalt or whomever the manufacturer of the sump or the heater whichever broke on you. That’s absolutely insane! Mmmmmh no this video has made me never purchase a cobalt item ever.

  3. Your stingrays are dead…rookie. (unless they died from old age)
    3:30, Sad.
    3:45, Angry…think about Steve Irwin. You are gonna want revenge on wild rays. All rays die anyway, "Since my stingrays died, you wild ones out here in the ocean are going to die too…because I am PISSED TO THE MAXIMUM and will NEVER forget what happened to my deceased rays!!" You must have vengeance in your heart to balance the sorrow and other feelings.

  4. The fact of the matter, is that company is responsible. Why you did not try and hold them responsible, I have no idea. They knew there was a Issue and kept selling the heaters with out doing a recall. You are basically making a excuse for that company. Not only it cost you your animals, but almost your life… Give me a break Just from your video I would never buy there product….

  5. Why did I not see this video before I purchased my heater? My Cobalt Aquatics Neo-therm heater malfunctioned today and kill off everything in my saltwater system. So devastated. Was looking through YouTube to see if anyone else has had issues with this model. I understand that all heaters can malfunction, but I have only had the heater for three weeks. I am still in shock and at a loss about it. Had I known about all the issues its had over the years, I would have chose a differently.

    Thank you for everything you post. I am a returning hobbyist/enthusiast this year after a 12 year hiatus. I started off with a freshwater system many years ago with a hodgepodge selection of fish. Had tried and failed at a saltwater system back then too. Due to moving to a new house and traveling for work back then, I just never set a system back up. But early this year I started watching your channel and the desire and need to get my own going kicked in again. Thank you for helping me make that decision.I especially found all the older actual DIY stuff educational and helpful. Not that I'm going to build a giant tank in my apartment, but was so cool to learn how and watch. Right now I am giving a marine system another go before getting a smaller freshwater system. Well, was doing marine till the heater killed everything in it.

    But again. Thank you for everything you post. I have learned a bunch from ya.

  6. You are not a 'hobbyist', you clearly have a passion for the fish and other aquatic specimens you keep. You may not be able to interact with them the same as say a cat or a dog, but through your videos you've allowed people to see your passion and I hope that they will realise that fish are just not pretty objects to look at that sit in a tank. I hope people realise the hard work and dedication it takes and share the same passion that you have



The BIG fish deal!

The FIRST 360 aquarium channel vlog (360 video)