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Availability:
In Stock.
Arrives
Thursday, Jul 9
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Style: E300
Pattern Name: Heater
Features
- Continuously monitors and displays aquarium water temperature in real time
- Intelligent digital microprocessor monitoring system with dual temperature sensors
- Ensures the safety and well-being of your aquarium inhabitants
- Precision temperature control allows settings in 0.5-degree increments
- Integrated fish guard provides advanced protection
Description
The most technologically advanced aquarium heater available today, Fluval E300 Advanced Electronic Heater with VueTech technology delivers peace of mind thanks to several excellent features.Equipped with an intelligent digital microprocessor monitoring system with dual temperature sensors, this heater continuously monitors and displays aquarium water temperature, ensuring the safety and well-being of your aquarium inhabitants.
Brand: Fluval
Capacity: 375 liters
Power Source: Corded Electric
Color: Blue
Wattage: 300 watts
Power Source: Corded Electric
Wattage: 300 watts
Voltage: 230 Volts
Heat Output: 300 Watts
Mount Type: Slim mounting bracket
Is Electric: Yes
Capacity: 375 liters
Item Weight: 0.37 Kilograms
Color: Blue
Style Name: E300
Material Type: Plastic
Brand Name: Fluval
Model Number: A774
Manufacturer: Rolf C. Hagen (USA) Corp.
Manufacturer Warranty Description: 5 years; fluval e series heaters are guaranteed against defects in material or workmanship under normal aquarium usage and service for 5 years. We offer a 5 year guarantee on all nonreplaceable parts which means that the heater will be repaired or replaced at the manufacturer's discretion, free of charge, when the complete heater is returned with proof of purchase and postage paid. This warranty does not apply to any heater that has been subjected to misuse, negligence, or tampering. No liability is assumed with respect to loss or damage to livestock or personal property irrespective of the cause thereof.
UPC: 015561107747 015561014168
Global Trade Identification Number: 47
Manufacturer Part Number: A774
Included Components: Fluval Advance Electronic Aquarium Heater (300 Watt)
Unit Count: 1.0 Count
Item Type Name: HAGEN FLUVAL E 300W HEATER
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Thursday, Jul 9
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Style: E100
Pattern Name: Heater
I spent a LOT of time figuring out which heaters to get to replace my eheim jager heaters that I'd used for 20+ years. In reading all the reviews of every heater and trying a bunch of different ones, the E series from Fluval was far and away the winner. I have been in the hobby 40+ years and have had that dreaded moment when you come home to a tank of dead fish b/c the heater malfunctioned. NO ONE in reviews for this heater had talked about that when I started shopping, and with the 8 I now I have, I can report the same - NO PROBLEMS - my tanks stay where they are supposed to! I've also had glass on heaters break - becoming a live wire in the fish tank. With these heaters - again, NO PROBLEMS - and the reviews support it. This heater is strong, and built to be nearly indestructible. I've also had, and always had, heaters that became difficult to adjust over time. That would slowly heat to a lower or higher temperature, and that became very difficult to adjust. This has led to disease outbreaks due to temperature fluctuations. With this heater - I've again had NO PROBLEMS! Most of the complaints I saw about this heater were due to seeing LF - Low Flow blinking. I figured, if that was the biggest problem I'd have, then this heater was a HUGE WIN, and it has been. Not to say I haven't seen the dreaded LF indicator, but, I would state that I've always been able to address it. I run canister filters on all of my fish tanks and on all 8 of them, changing how the water flows out of the canister filter in the tank has resolved the issue. Sometimes it takes some fiddling - I'll give you that, but all 8 of mine work perfectly and when I see LF - I know something has changed in the tank and is causing issues (for me - typically it is related to large plants blocking flow). I LOVE the always on display, like love, love, love it! At a glance I can tell if there are problems in temperature. I also appreciate how easy it is to adjust temperature, just flick the switch left or right and you are good. Easy Peasy. In the end - I started with one, and slowly, over 4 years, have replaced 8 or my 10 heaters with these, and I couldn't be happier. They are easily the best heater I've had in my many years keeping fish. That said - I do have 2 complaints. 1 - Replacing the rubber suction cups is currently very difficult b/c Fluval doesn't make replacements very available. 2 - It is very difficult to clean the heater housing if (when!) it becomes covered with hair or brown brush algae. Neither of those things are deal breakers for me, but are worth mentioning.
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Reviewed in the United States on February 28, 2026 Reviewed in the United States on February 28, 2026 by Russell D. Carroll
Style: E200
Pattern Name: Heater
i bought this for my 55 gallon red eared slider tank, and it works great. it’s easy to set up and move around, the suction cups allow you to adjust how far in the water it goes. it’s not too big and fits in my tank well. it keeps my turtles water a comfortable temperature, even when the rest of the room is cold. i love that it comes with protective plastic casing, so i don’t have to worry about my destructive turtle trying to eat it!
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Reviewed in the United States on April 9, 2026 by Josie
Style: E100
Pattern Name: Heater
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.
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Reviewed in the United States on December 3, 2017 by Matt
Style: E300
Pattern Name: Heater
I've used at least 6 brands of heaters over the years, and this Fluval wins hands down. 1) nice looking 2) plastic sheathing guards the fish. They like to lay on it. 3) temp gauge is ACCURATE! The display says 77.5 and my $$$ insta-read BBQ thermometer says 77.5. (the reason i say this is that oodles of cheap fish thermometers _vary_. Test it with a reliable thermometer.) 4) cheap on black friday. 5) not all that long. Usually the higher the wattage, the longer the thermostat. The 300 watt fits in my 23 inch wide 25 Gal just fine. I like to put mine horizontal. Its so nice looking you wont notice it. 6) heats QUICK. A 37 gallon cold tank was 77.5 the next morning. 7) temp display is not at all bright so its not going to light up the room at night. 8) thermometer measures the temp of the WATER, not the heater glass like most heaters. Its surprising to learn how temps vary in your tank. Temps at top vs temps at the bottom. And the glass skews things even more. Measuring by water temp fixes all of those variables as long as you have water flow. I liked this heater so much, I ordered a second one from amazon at regular price the next day. Haven't had any problems with low-flow. The manual states that the heater can be taken apart and cleaned if it ever needs it. EDIT: Just ordered a 3rd. The price keeps going up! Still amazed the display says 77.5 and another therm says 77.5. Exact. I see the other semi-favorable reviews. Not sure why my 2 tanks are so exact when others fluctuate. I do have the glass top and plastic guards cut snug to prevent heat loss / evaporation... maybe that's also a requirement ? Maybe you are using a cheap therm. from petsmart ? I have a mercury one and its are so far off, its crazy. UPDATE: its been 1 year and now one isn't heating right anymore. Its on 79.5 but the tank is at 75. Unplugged it for a couple hours and it reset itsself a bit better. Im getting a new one just to be safe.
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Reviewed in the United States on December 12, 2011 by moveeedude
Style: E300
Pattern Name: Heater
This heater is great, I love how it has a digital temperature sensor so you can easily see the temperature of the water and how easy it is to adjust the temperature as well. Installation is straightforward like a heaters but this model does have an adjustable mount that lets you adjust it up and down and it also comes with an angle mount so you can place the heater in the corner of the tank. I had to purchase two because of the size of my tank so I wouldn’t have any cold spots but over all great item and very happy with my purchase.
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Reviewed in the United States on May 8, 2026 Reviewed in the United States on May 8, 2026 by Jay Galindo
Style: E300
Pattern Name: Heater
Zero stars. I have this in a 75 gallon planted tank with LOTS of driftwood and deep substrate so there is MAYBE 65 gallons of water total. Bought the E300 rated for 100 gallons. Let me count the ways I hate this useless heater that cant do its job on a tank half the size its rated for: 1 - Does not get anywhere near set temperature in a room where ambient temps are a steady 72 F. I had it set for 77, it got to about 73 or 74. Thats only 1 or 2 degrees warmer than the room. I can rub two sticks together and get more heat than that. 2 - Because it does not heat water properly, the display flashes a bright neon blue forever that is so bright it throws blinking shadows all over the room at night. I cannot emphasize enough HOW HORRIBLE AND ANNOYING THIS FEATURE IS. Think trashy motel room with blue neon lights blinking in through the window that keep you awake forever. Its SO RIDICULIUSLY BRIGHT. Put a resistor in there guys so I dont feel like a movie villian hiding out in a Las Vegas motel. Holy cow. 3 - It does not matter where you put this heater, it will also flash LF in bright neon blue indicating water is not moving around it. I even dangled it DIRECTLY IN THE OUT FLOW OF THE FILTER AND IT STILL FLASHED LF! Next to the intake, in the churning corner, floating directly in the flowing water shooting out of the filter, none of it mattered, neon blue LF flashed on this piece of garbage wherever I put it. 4 - The housing. Horrible. Looks like it will protect fish and plants, actually just makes it impossible to secure the heater to the tank where you want it. 5 - The toggle switch used to set the temperature is horrible. Its like trying to steer a car that is supposed to have power steering but doesnt and it makes tapping the temperature setting up or down a horrible pain...not that it matters anyway because IT DOES NOT HEAT THE WATER. 6 - Oh yeah, IT DOES NOT HEAT THE WATER, so much so that my fish literally have to camp on it. So at least it gets mildly warm or something? Lol. 7 - Its expensive and I could have just got a simple glass cased heater that doesnt light up my room like a flashing neon sign for like half the price. Garbage. I want my money back. Had aquariums for over 15 years. This thing is a standout...in all the wrong ways.
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Reviewed in the United States on May 12, 2024 by steve t
Style: E200
Pattern Name: Heater
The Fluval E200 electronic heater has been rock solid in my aquarium. What really sets it apart is the temperature stability and accuracy. Once set, it maintains the water temperature extremely well without noticeable swings, which is critical for fish health. The digital display is clear and easy to read, and I appreciate being able to adjust the temperature precisely instead of guessing with a dial. The heater reacts quickly when the temperature drops and shuts off properly once the target range is reached. Build quality feels premium and well thought out. The protective casing adds peace of mind, especially in tanks with active fish. It also feels safer than traditional glass heaters thanks to its internal safety features. Pros: • Very accurate temperature control • Clear digital display • Stable heating with minimal fluctuation • Strong safety design and quality build • Ideal for medium to larger aquariums Cons: • Higher price than basic heaters • Takes a bit of space in smaller tanks Overall, this is a reliable, high-quality heater that’s worth the investment if you care about consistency and safety. Perfect for anyone upgrading from basic heaters or running a larger, more sensitive setup.
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Reviewed in the United States on December 23, 2025 by Ahmed Radhy
Style: E300
Pattern Name: 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.
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Reviewed in the United States on April 11, 2012 by Fish 123