Review on Mini Fluval Marina Submersible Aquarium Heater: Effective Heating Solution for Fish Tanks by Amber Jensen

While I love the fact that this heater fits my Fluval Spec V perfectly, I haven't had any luck with it. The first came with a broken bracket and missing the lower bumper, but as always, Revain have been great with returns and replacements. The second worked from January 20 to February 17. On the 17th I picked it up to raise the temperature and noticed that the tube was filled with water. I'm very glad I discovered this before the short happened and killed my fish, and I'm very glad I got rid of it without electrocuting myself or bystanders. After unplugging it and removing it from the tank, it was clear that water was leaking through the seal (where the glass meets the controller on top). I've seen a few posts on tank forums about people having this problem and the ensuing debate as to what they mean by "immersion heater" when they refer to it as "immersion heater". To be clear, mine wasn't level on the tank or anything, and most of the time the top was about 1/2 inch out of the water. In any case, be careful if you think this heater can work underwater (like I do).