Features:

  • Dual temperature sensors provide accurate and real time water temperatures
  • LCD temperature display available in both Fahrenheit and Celsius; Range of 68 to 93 degrees Fahrenheit
  • Fast heat technology built with a safety shut-off; Integrated fish guard to protect fish and invertebrates
  • Equipped with a slim profile mounting bracket; Colored display alert system
  • Suitable for aquariums up to 100 gallons; 300 watts; 5 year warranty
  • Check out user manual under Product details before using the item.
  • The heater is factory calibrated. Variables such as lower room temperature, wide fluctuations, lack of an aquarium cover, presence of submersible pumps and filters, aquarium placement in proximity to cooling sources, may require a higher wattage for proper control. The volumes indicated are approximate values corresponding to water temperatures up to 26°C/78°F with a room temperature of 20°C/68°F. If the ambient temperature is higher than the set temperature of at least 1°C/2°F, or external sources of heat elevate the aquarium temperature more than 1°C/2°F, the LCD display will remain red until conditions change
One of the best aquarium heaters you can buy

This is the Cadillac of aquarium heaters. I purchased the 300W version for my 55-gallon aquarium. It may be a little oversized for that volume, but the 200W was out of stock and a little extra wattage won’t be an issue for me. The heater guard is very nice too, it can easily be removed for cleaning and my favorite part of the guard is that the back plate with the suction cups can be detached from the heater so you can always return it to the same position. The light on the heater is also very nice and it will tell you if water is too stagnant. I really appreciate failsafes like that on a product you want to just turn on and forget while it does the job it was built to do. If you’re looking to save money there are probably reliable heaters out there you can find for less than this with less bells and whistles, but Fluval makes quality products in my experience and this heater is no exception. If you’re unsure how many watts you need, just google it and remember that water circulation will be more important the larger your tank is. I also purchased a fluval wireless thermometer that reads room temp and tank temp from a sensor on the back which comes into contact with the glass rather than having a wired probe to place inside the tank.

Works great with a few tips.

I generally don't leave reviews for products, even ones I love, but I wanted to clear up an issue people were having with this heater in comparison to others. The temperature indication is spot on, very accurate. The design is sleek and well constructed. The issue I was having with this unit was not being able to maintain tank temperature in a very cold room, even though I oversized the wattage/gallons ratio by over double the recommended specifications. I believe the shrouding around the glass mildly hinders heat distribution so it is important that this unit gets adequate flow from the filter. I placed the heater directly under my filter return but still randomly had scenarios where the temperature dropped and stayed in the blue, even for a couple days. Then it would rise to green and maintain no problem. What I realized over time was whenever I did water changes or added water, the temperature dropped that night, even if the water added was warmer than the tank water. As the water level dropped over the next few days from evaporation, the temperature rose back up to normal. My hypothesis: If the water level in the tank is a hair too high, there is less disturbance created from the filter return, even though you are still achieving the same turnover rate. Try either lowering the water level in half inch increments until the temperature is able to maintain, or try rotating the heater sideways to achieve more flow through the shrouding. I recommend the first option because turning the heater sideways looks ridiculous with the digital display. I now maintain 77-78 degrees constantly in a 55 degree room and would purchase this heater again. Fluval makes excellent products.

Best heater I've had in 30 years

I have a 30 year old 44 gallon fresh tropical water pentagon shaped aquarium. I use both an under gravel filter driven with a power head and a canister filter. A month ago my heater failed so I quickly did a search all over Amazon to find a reliable replacement. The reviews on this unit are all over the place! So I took a chance and ordered it. With both filters running and the location of the heater I have plenty of current so no low flow issues. Set up was incredibly easy and exceptionally accurate. I heat my tank at 76 degrees and by the time this heater arrived at my door the tank was down to 68 degrees. Over all the years of maintaining an aquarium I wasn't about to raise the temperature back up to 76 in five hours. I gradually raised the temperature by two degrees each day for four days so the fish would slowly acclimate. This heater had no problems with this approach. Once it reached 76 degrees it maintained it within half a degree despite the house air temperature being 68 during the day and 64 degrees at night. Here's the unique thing about the design of this heater, the temperature near the bottom of the tank is almost identical to the temperature near the surface. I have never had a heater that was capable of this. I don't know if Fluval used black magic to accomplish this or if it's just unique to my tank design, filtration, and heater placement. I have only had this unit for four weeks but am very please with it. I will update this review should any problems arise.

Fluval E 200 - Best Aquarium Heater I've Ever Owned

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.

Finally a sophisticated Heater

To start off, I don't get all the 1 star reviews. If "LF" is a problem, it's relatively easy to fix. Circulation is important, esp. in larger tanks, so that the water is the same temperature everywhere. I've been using this 300 watt heater for about 3 weeks now and so far, I'm pretty impressed. I have a 55 gal freshwater tank with an eheim canister filter, that has the inlet on one end of the tank and the outlet via spray bar on the other end of the tank. My old heater wasn't working right anymore and my tank temperature had been around 76.5°F until I got the new heater. I followed the instruction to allow the heater to adjust first to the ambient water temperature, before connecting it to power. I then set the temperature to 78°F. Placed it in the immediate vicinity of the spray bar in hopes to get the water circulation that this heater requires. Well, that wasn't working so great as it started displaying LF (low flow) about 15-20 minutes into warming up the water. So I moved it to sit in the bubbles of an aeration bar sitting against the back wall of the tank. And voila, just like that, LF problem solved. :) Temperature in my home has been varying - NE Florida spring weather is unpredictable and my house goes from 68 to 78 all the time. The heater has been consistently keeping the temperature within half a degree of its set value. I love the ease of setting the temperature with the swivel knob at the top and the digital temperature display is a neat feature. I have a separate digital thermometer to verify the heater performance. So far it has been spot on. It's fully encased, so tank inhabitants are safe from harm. A definite step up from the hard to adjust and unreliable heaters I've previously owned. I will post photo/video later and update this review if anything changes.

LF Error? Just put it above an air stone/bubbler

Great heater! I have it on my 65 gallon tank and it has been keeping the temperature stable. You do have to play with its placement a little in order to get the right water flow. Otherwise it'll keep flashing LF (Low flow) all the time. I found that placing it above a small air stone works very well in keeping the right flow. You need enough water movement across it in order to heat the tank properly. Otherwise it'll just heat that little spot where it's at.

Nice heater!

Received the item today, product box was a bit dented on the sides and torn on top but the unit was alright, no visible scratches nor cracks upon inspection. The product looks pretty cool, replaced my old heater which I had to calibrate prior to first use and re calibrate every now and then, it was just complicated for me and I had to spend a lot of time doing so. Hopefully this one will give me peace of mind😃👍🏻 Update: My 60G frag tank temperature had never been so stable since I installed this heater in my system, of course, its working together with a 1/4HP chiller. Chiller set at 78'F, heater set at 76.5'F, synergistically, heater reads between 77.5-77.0'F throughout the day and night even though the ambient temperature in my shed reads 72'F to as low as 69'F. In short, Fluval E heaters keep a very, very stable tank temperature compared to the one that I previously used with unpredictable temperature swings.

Your tank needs this

Bought it as a Amazon warehouse deal. It was missing one of the three suction cups but otherwise fine. Thought it was malfunctioning until I realized that the previous owner had set it to 85 degrees. Once I adjusted it back down to 77, it works great! Digital display is very cool and comforting when you have a couple hundred dollars of family members under its management. Very obvious if heater is malfunctioning or not big enough as the display flashes green/ blue if under temp and red if over temp. Even on the back wall of my 75 gallon tank, it was very noticeable. Super happy!

Best Heater Ever

Best Heater I've Ever Used! I've spent hundreds of dollars and stressing my poor fish in search of a heater that keeps them at 79-80 degrees Fahrenheit without fluctuating. I tried various wattages of recommended brands like Marineland and Eheim Jager. Marineland units shot up to 85 degrees after the first week. It never mattered what setting or size, and I always followed directions for handling them. Eheim Jager never warmed up enough and fluctuated like crazy (except for one out of 4. I still don't trust it and will replace). This Fluvall Heater is going to be the one I choose for all my aquariums (4). It NEVER fluctuates--and I mean NEVER. I have tropical freshwater fish and my room is freezing--at least 15-18 degrees below 79 degrees Fahrenheit at all times. I feel so much calmer knowing that my fish cannot scald themselves on the heater because of the very intelligent enclosure around the unit. Why doesn't every manufacture put one on their heaters? Also, I am able to quickly glance at the digital, easy-to-see numbers that are large enough I don't have to put on my glasses. All the other brands were a huge water-splashing mess bc I inevitably had to fumble around in the aquarium to get the damn dial to angle so I can read the tiny numbers. I cannot express how pleased and satisfied I am with this unit. It has solved a problem I had almost given up hope would be solvable. Thank God, literally. My fish can live in comfort and health..

Easy to set, easy to read.

Did take over 24 hours to stabilize the temperature in my 65 gallon tank (bought in a hurry after failure of 2nd Eheim heater w/in a year!), but once there is holding temp nicely. Does read +/- 1.5 degrees lower than my external digital thermometer. Lever to adjust temp is easy to use, accessible. Lighted digital display in tank is a bit unsightly, but it is easy to read. Color display instantly shows if temp is OK or too low, and the low flow indicator is also handy. On balance pleased with the way it is working, will consider it perfect if it keeps working for a reasonable useful lifetime.

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