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Fluval M Series Heaters – Specs, Dimensions, etc.

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heater for fish tank

Fluval is one of many companies that provide heaters, aquariums, lighting, and other products for the aquarium keeping hobby. The company has been around since 1975 and continues to release products for all to enjoy. This article will specifically discuss the many different-sized M Series Heaters made by Fluval. We will begin with the small Fluval M50 Heater, and make our way to the largest of the series, which is the Fluval M300 Heater.

General Fluval M Series Heater Information

Before we move onto the details of each heater, let’s discuss some of the features that the heaters share between them. The following are features that this heater series contains.

Mirrored Finish & Fully Submersible Design

A very interesting feature that can be seen with each of these filters is that they all have a mirrored finish. The goal of this mirrored finish is to allow the heater itself to blend into the surroundings. It does this by reflecting the aquarium’s colors to camouflage itself.

Fluval M Series Heaters are designed to allow full submersion. This is a fantastic feature because it allows you to hide them behind decor a bit easier. An added bonus to this is that you can also position this heater series horizontally. The only flaw to fully submerging your heater is that you’ll have to dip your hand into your aquarium to change the temperature.

Computer Calibrated Thermostat & Temperature Control Dial

This heater series comes equipped with a computer-calibrated thermostat. This makes fish-keeping a little easier because the thermostat should sense when the water hits the desired temperature and shut off. Once the water temperature drops, the heater should fire back up and bring the temp. up again.

The Fluval M Series heaters come with a fairly straightforward control dial that allows you to adjust your temperature to your needs. You can adjust and turn your dial to a wide range of temperatures. On the low end, you can set your temperature to 66° F, and 86°F on the high end. This provides you with a large range of fish of different species.

Fluval M50 A781

The Fluval M50 Submersible Heater is the smallest in this series of heaters. It is a 50 watt heater that is made to be used for aquariums up to 15 gallons (57 Liters). This heater has a fairly small footprint. It has a footprint of 11″ x 1″ x 1″. This may be a little large for Nano-fish tanks but should work very well for 10-gallon aquariums. Be sure to check out the Fluval M50 on Amazon!

Fluval M100 A782

Next, regarding size is the Fluval M100 Submersible Heater. This 100 W aquarium heater is an excellent choice for fish tanks up to 30 gallons (100 Liters). Although it uses twice as much wattage and can heat more aquarium water, Fluval M100 Heaters still has the same footprint as the M50. The M100 footprint is 11″ x 1″ x 1″. If you can afford a larger heater, I would recommend picking this one up over the Fluval M50 Heater. Before we move ahead, consider checking out the Fluval M100 on Amazon!

Fluval M150 A783

The Fluval M150 Submersible Heater is rated for aquariums up to 45 gallons (150 Liters). This model in particular uses 150 watts which is a bit more than the M50 and M100. The M150 Heater is also the first that is a little larger. It has a footprint of 13″ x 1″ x 1″. Not much larger, but it can make a difference. Overall, it is a good heater but you will likely need to get the larger M200 for something like a 55-gallon fish tank. You can pick up the Fluval M150 on Amazon!

Fluval M200 A784

The next heater on this list is the Fluval M200 Submersible Heater. This heater is rated for fish tanks up to 65 gallons (245 Liters). This is a 200 W heater that shares the same dimensions as the Fluval M150. Those dimensions are 13″ x 1″ x 1″. This heater is an excellent candidate for 55 gallons aquariums but falls short as a recommendation for 75-gallon aquariums or larger. For larger aquariums, I recommend the Fluval M300. Be sure to check out the Fluval M200 Heater on Amazon!

Fluval M300 A787

The final and largest heater in this series is the Fluval M300. This submersible heater is rated for aquariums up to 80 gallons (302 Liters). This heater uses 300 W to warm your fish tank so it packs a punch. As stated above, this is the largest of the M Series heaters in both wattage and length. The Fluval M300 Submersible Heater measures 15″ x 1″ x 1″. Large aquariums should easily hide this heater regardless of size. At the time of writing this, the Fluval M300 is not available on Amazon, but be sure to check it out on the FluvalAquatics website!

Final Notes

The Fluval M Series Submersible Heaters are just one of many types of heaters available to purchase. I have personally used these heaters for both freshwater and saltwater aquarium and am consistently happy with the results. If you have any experiences or comments about this heater series please share them with me! If you’re looking for heaters from different brands, take a look at the 6 Best Aquarium Heaters for Freshwater & Saltwater Fish Tanks!