Rena SmartHeater Aquarium Heater, 50W

I recently got the Rena Smartheater after a couple episodes of burnt fish from my old, conventional glass tube heater.No, they were literally burnt to a crisp, but certain types of fish like to rest on available perches in any given tank. Even if your tank is well planted with many available hiding places and good sized leaves like mine is, chances are your fish at some point will come to "rest" on or in the space between the heater and the glass side of the tank that the heater is adhered to.Bettas and loaches in particular like to take a rest from the filter current, especially if they can do so near the top of the tank to grab air now and again.I could see spots where the fish received these burns and I felt bad as soon as I realized that these burns must be coming from their contact with the heater.And though the most inexpensive way to heat a small 5-20 gallon tank is to use the cheap, standard glass tube stick-on-side heaters, I don't like them for this reason alone.I researched on the internet and found that the Rena appears to be just about the only hang-on-side aquarium tank heater that does not have an exposed heat source on which fish can burn themselves. It seems to heat by some sort of internal heat convection in which water is drawn up through the slats on the bottom and expelled gently, imperceptibly through the top. The top hole itself glows red when the heater is on and shuts off when the heater is not actively heating to show you that it is working.It seems to do the job well, keeping my tank's temperature apparently stable. And it is built quite robustly, with better build quality and more solidness than the glass tube heaters that I have previously tried.Fish burning themselves on an exposed heating element is not as uncommon as you would think. The Rena heaters aren't inexpensive, but they do the job safely, which is reason enough to recommend it.

These heaters stop working way too soon. Will not buy another.

I really like the innovative concept behind the way this heater integrates with the Rena SmartFilter as an alternate for the filter intake tube. This heater design would seem to present less danger of a hot element coming into contact with one of the tank dwellers and would also seem to be less fragile/susceptible to damage as compared to the typical stand-alone glass tube heaters. I docked the product one star for concerns over long-term reliability of these units simce I've had to replace these more often than other stand-alone glass heater units I've used in the past. However, the fact that I'm still using these despite the occasional need for replacement says something for how much I like this innovative design. If you've got a Rena SmartFilter already, I'd recommend giving these a try to see what you think. Otherwise, I'd have to say that buying a Rena SmartFilter just to be able to make use of this heater might be a poor decision due to other deficiencies inherent in the SmartFilter design... that is, unless they've updated the SmartFilter design since the ones I purchased. If you'd like to know more about my concerns/experiences regarding my Rena SmartFilter products, take a look at my other reviews which include a review of the Rena SmartFilter 30 product (of which I presently own/use two).

This heater cracked open in the middle of the night and I woke up to my fire alarm and smoke coming out of my aquarium. Thankfully my two turtles seem to be ok.

I used this about 6 to 7 years ago when I had and arowana. Now I have a nano tank with a improvised refugium system. Unfortunately because of the nature which is saltwater and the size of tank its hard to find the size and capability.I overheated a few time, experimented with different one like the one with digital thermometer and two separate sensors. I was really dissappointed with Fluval E smart heater that I had to return it twice and the third time I had it. The only downside to this heater is its hard to find now. Im now sure if they discontinued this or only available at UK that it needs to be imported.I hope this help guys.Take care and thank you for reading.

This works as a great heater, but doesn't hook up that well as an intake. It seemed to have gotten lose, and on of my fish get sucked up into the filter motor. It could have been user error, but just make sure you really check it out and have goo extra tubbing before using it as a intake with smaller fish.

Great heater until it cracked open and leaked some nasty oil in my tank and killed all my fish. Stank up the house as well. If you have ever smelled differential oil then you know what it smelled like. Horrible experience and I will be writing the company and when they fail to respond I will be contacting the BBB.

After killing a tank full of goldfish, I've been really careful about the tropical fish that replaced them. I am almost to the point of paranoid about conditions in the tank. The heater that came with the aquarium didn't seem to be doing a good job, so after researching heaters, I purchased the Rena SmartHeater. It has really taken the worry out of my concern for the temperature. It keeps it at exactly what I set it at. I bought the 50W because it was recommended in one article I read, for 20gal. But another article said you should get 100W for 20gal. So we'll see who's right. But so far, 50W is working fine.