Fluval E 300 Watt Electronic Heater

I read many reviews before I made my mind up on this heater. I will say I am sold on FLUVAL, as I currently own 2, 306 filters, 2, Q2 air pumps, and lastly 1, E200 and one E300 heater. I could not make up my mind with the first E200 or go with a E300 for a 55, I have two, am happy with both so this is about both since nothing but capacity changes with them, functions are the same.I can say, I had the old school type heaters, which seemed ok but had a hard time setting my temps just right. You know the drill, set the dial and wait a day, turn it back some, turn it up some, what a waste. With this heater it is SET and FORGET.With the color changing display you know what it is doing, or more so if there is a temp change more than 1 degree, it lets you know. I do have thermometers, the strip kind, I know I should get the real ones, howerver as the Fluval gives a real time, real temp display I do not think I will, I have also and do still, since these are new to me, check with a laser temp meter, so far both are to with in half a degree of the setting,Yes they do need water flow to work, so if you have HOB filter they would need to be close to that, I use canister filters with spray bar, so no problem there.One BIG plus for me, in my thoughts is the gaurd that keeps my fishes from rubbing up against a hot tube and burning themselves.The side mount is also usefull, as I have it on one of my tanks, my fish like the corner I would like to put it in, best second location is to the front, and the agles attachment lets you veiw the display.All in all, Very good, accurate heater, great display, great warnings if temp changes. I am so far happy with this unit, Hope if you a thinking of getting one of these do not hold back, In my opinion they work very well and you will be glad you did.

First off, I'm a Mechanical Engineer with 31 years of experience and have a considerable amount of experience related to heat transfer. I've also kept aquariums for 36 years and currently have 3. I've had a Fluval E 200 watt heater in a 75 gallon tank for almost 3 years and it's performed flawlessly. I've read tons of reviews stating the low flow warning is a problem, but that warning is an attribute of this heater. Tank heaters are very compact for the amount of heat they generate and must exchange the heat to their surroundings efficiently or they'll burn themselves out. Just imagine grabbing an old fashioned 100 watt incandescent light bulb that's been on for several minutes .... now imagine that it's a 200 or 300 watt bulb! Also think about the fact that the largest portable space heater you can buy and plug into a standard 120 Volt wall receptacle is 1500 watts. That'll give you a perspective of how much energy 200 or 300 watts is. So yes, you absolutely need water flowing over the heater to carry heat off as opposed to it only heating the immediate area and then shutting off. My 75 gallon tank is fully covered and is in my basement which is typically 63 - 66 degrees in the winter and this 200 watt heater has always kept it within 1/2 degree of the 77 degree setting. I've had many different tank heaters through the years and will never buy anything but these again. As many others have said, being able to just glance over and see the green display indicating that the water temp is within 2 degrees of set point is very nice! I literally look at it every night before going to bed and casually glance at it during the day without even focusing on what the temp actually is. I'm sure many have had defective units but these heaters are wonderful when functioning properly. Oh and I put zero value into reviews stating any heater won't work when the operating conditions aren't given. How many gallons is the tank, what's the ambient air temp, is the aquarium fully covered, etc, need to be known to evaluate whether sufficiently sized. Putting a 1500 watt heater in a well insulated 300 square foot room in your house will keep it toasty; putting that same heater in your outdoor shed in the winter ..... won't help much. One last thing, I'm absolutely not a fan of putting a heater that's considerably larger than required in a tank as I've seen advised many times. All heaters will eventually fail and if it fails in the on mode, I don't want to cook my fish. I'd much rather have 2 smaller heaters in a tank than 1 over sized heater. That way if one fails and won't shut off, the other heater either won't come on at all, or will intermittently cycle to make up what the stuck heater can't do. Heaters are designed to work and will last just fine even if they run a majority of the time. In fact many products will actually last longer if they can just run as opposed to "short cycling" as when they're considerably over sized. I have a Clown Loach that's between 8 - 10 years old and I have no intention of allowing a faulty heater to kill it or any other fish under my watch.

great heater for a 55 gallon tank. Love the digital readout so I can keep a eye on the temp.

Firstly, I like the look of this unit. Also, the digital readout is neat. The adjustments are incredibly easy. Once positioned correctly, it holds temp well. That being said, it is finicky with placement. I initially had it in the center of my tank, vertically, with the red knob protruding, exactly like the directions say. All was well, until my first water change. After that I kept getting the error that it needed more circulation. You can unplug it and it will reset, but it continued to eventually error. So, I moved one of my large airstone directly underneath, and it has worked flawlessly ever since. So make sure it is placed where there is plenty of movement.I have read that others have had luck with placing it fully submerged horizontally. But I chose to stick with what the directions say. Plus horizontally would mean the digital readout would be sideways.I have the 300 watt in a 55 gallon. I have the temp set at 78.5°. My accurate thermometer reads between 78.5° and 78.9° at all times. Not too bad. My Eheim was a bit more stable, but really sucked to try to change the temp as the dial was awful. Plus after 2 years I started to notice some moisture in the glass, which is what led me to this purchase.