Fluval M Series Heater Unboxed & Reviewed 2021 (A Reliable Workhorse?)

When I look at Fluvals M series, I think throw-back. Nothing fancy, just accuracy, reliability, and durability.

So, how does the M series stand up to the more fancy E series? And what about other heaters in the same class?

I bought 5 heaters, including the M series, and tested them against each other in my tanks to see how they perform. In this guide, I’ll share with you my results so you can make the right decision on which aquarium heater is right for you,

TLDR – Fluval M Series Heater Review

The Fluval M200 is an excellent choice if you’re looking for a simple to use, old school style heater.

I bought a new M200 for comparison between it and five other heaters for a comprehensive review that looked at all their features. 

Plus, I’ve been running a M200 in one of my 40 gallon (151 liter) tanks for years.

So, I’ve got lots of experience with this heater and I feel comfortable enthusiastically recommending it.

This heater performed well in testing. It’s easy to install and calibrate and it provided very consistent temperatures.

My gripes are really minor: 

  • Glass exterior
  • No built-in heater guard 
  • No overheat or dry sensor

However, these are all issues common to the vast majority of heaters on the market. It’s not like they’re unique faults of the M200. 

The Fluval E200 did come out on top overall in the head-to-head challenge because it has a few more optional features. But, if you’re looking for a simple and reliable heater, the M200 is a great choice.

Sale
Fluval M200 Submersible Heater, 200-Watt Heater for Aquariums up to 65 Gal., A784
Fluval M200 Submersible Heater, 200-Watt Heater for Aquariums up to 65 Gal., A784

    Last update on 2021-09-29 / Commissions Earned / Images from Amazon Product Advertising API

    What’s in the Box?

    Fluval m200 aquarium heater unboxed

    Not much in the box on this one, just the heater and an instructional pamphlet. Simple.

    The bracket and suction cups are already installed for you. So, you can just take the heater out of the package and just immediately stick it to the back of the tank. It’s that easy peasy to get it installed.

    The very top of the heater should stick out of the water and you want to make sure that evaporation won’t drop the water below the minimum water line on the heater.

    Easy to read temperature settings – simple to read temperature dial on the top of the heater tube.

    Durability – the exterior is made of glass. I’d prefer a tougher material, but I must say, the one I’ve had for several years has proven to be sturdy. Always unplug any heater and give it time to cool before you remove it from the water to avoid cracking.

    Indicator light – there is a blue light that comes on during active heat mode. No standby light, sadly.

    Overheat/dry sensor – no overheat or dry sensor. Never, never run this heater outside of the water.

    Heater guard – this heater does not have a built in heater guard. 

    All of these tests were done with a 200 watt heater in a 55 gallon tank. If your tank is bigger or smaller, there are several other sizes of the Fluval M series heater that would work.

    How I Tested The Fluval M Series Aquarium Heater

    I tested this heater as part of a head-to-head comparison between five different heaters I purchased:

    1. Fluval E200
    2. Hygger 200 Digital Quartz Heater
    3. Fluval M200
    4. Eheim Jager Thermostat Aquarium Heater
    5. HITOP Adjustable PTC Aquarium Heater

    Each heater was installed in the 55 gallon (208 liter) cichlid tank in my living room and allowed to run for a week.

    I took a bunch of notes and pictures so I could document how things went along the way.

    I was looking at very specific criteria on which to base my judgements:

    • Installation – was it easy or hard to install this heater?
    • Calibration – how hard was it to get the heater to maintain the correct temperature in the tank? Could you set it and forget it or did you have to mess with it a bunch?
    • Consistency – did the heater hold the tank at a steady and consistent temperature throughout the day or were there noticeable temp swings?
    • Optional features – there are some features that I’ve found to be really useful over my  years of fish keeping:
      • Easy to read temperature settings – you really wouldn’t think that clear temperature controls would be an optional feature, but believe me, there are many heaters out there that have impossible to read or even nonexistent markings for the settings.
      • Durability – the outside of a heater can be made from a variety of materials, like ceramic, glass, plastic or titanium. Plastic and titanium aren’t vulnerable to cracks and shatters like glass and ceramic are. 
      • Indicator light – heaters have several different styles of indicator lights. Some have no indicator lights (which sucks!). Others have one indicator light that flicks on when the heating element is running. The best are heaters that have a light for active heating mode and another for standby mode. This lets you know the heater is plugged in and has power even if it’s not actively heating the water.
      • Overheat/dry sensor – an overheat sensor is meant to perform an emergency shutdown of the heating element if the water temperature gets too high. A dry sensor shuts down the heating element if it detects that the heater is running out of the water. This prevents overheating that can cause cracks, shatters, melting or even severe burns. My dad got a nasty burn from an aquarium heater. Seriously, no fun. Be careful!
      • Heater guard – even though it’s running underwater, an aquarium heater still gets hot enough to burn a fish that’s touches it. A heater guard is a plastic cage that surrounds the heater and keeps fish from touching it. 

    The tank I used to test the heaters is a standard 55 gallon. The room is climate controlled and has an average temperature of 70°F (24°C). The target temperature for the tank was 75°F (24°C).

    I placed a bunch of thermometers along the front of the tank. That made it easy to keep an eye on the temperature throughout the day.

    Also, I’ve used an M200 heater in one of my 40 gallon (151 liter) tanks for several years now. I bought a new one for testing and have found that the performance is very consistent.

    So, I’ve got lots of experience with this heater in particular, and I’m glad to share my insights about it.

    Sale
    Fluval M200 Submersible Heater, 200-Watt Heater for Aquariums up to 65 Gal., A784
    Fluval M200 Submersible Heater, 200-Watt Heater for Aquariums up to 65 Gal., A784

      Last update on 2021-09-29 / Commissions Earned / Images from Amazon Product Advertising API

      You can see the full round up aquarium heater review here

      Fluval M200 Review & Test Results

      I definitely have to say that this is a solid little heater. It’s not the most sophisticated thing on the market, but if you’re looking for an old school workhorse of a heater, this would be my number one choice. Make sure to put it in a high flow area so the heat will be dispersed throughout the tank.

      Installation takes all of about five minutes, super simple. Just stick the heater to the tank wall and plug it in. It was SO much easier than the HITOP, Hygger or even the Eheim heaters when it came to installation.

      The suction cups are really strong. The ones on the M200 that I’ve had for several years are still holding strong.

      I only had to tweak the temp settings two times to get it to hold at 75°F. If anything, you might need to turn this heater down a little bit, it’s quite efficient. The only heater that was easier to calibrate was the E200.

      Fluval m200 aquarium heater in fish tank

      Once I had the tank at 75°F, the M200 just kept it there with no problem. The temp stayed nice and steady for the rest of the week.

      It was much more consistent than the HITOP or Hygger heaters that I tested, way more in fact.

      I wish this heater came with a heater guard, like the Fluval E200 does. Fish can brush up against it and get burned so keep an eye out for fish trying to swim behind this heater.

      My other gripe is that the exterior is glass. I would have preferred shatterproof plastic or titanium. Be careful, rapid temperature swings can cause the heater to crack. 

      Like I said, I’ve been running one of these for several years, and I’ve had no cracks or shatters. This is aided by the fact that I diligently unplug all my heaters before I remove them or drain the tank.

      On a side note, I know this is subjective, but I can’t help liking the look of this heater. It’s got this mirrored finish that looks kind of modern and cool to me. Like it belongs in a laboratory. 

      The slightly fancier Fluval E200 ended up being my number one pick after comparing everything for the head-to-head challenge, but I also wouldn’t hesitate to buy another one of these M200s either.

      When it comes to old school style tube heaters, this gets my highest recommendation.

      Sale
      Fluval M200 Submersible Heater, 200-Watt Heater for Aquariums up to 65 Gal., A784
      Fluval M200 Submersible Heater, 200-Watt Heater for Aquariums up to 65 Gal., A784
        Fluval E200 Advanced Electronic Heater, 100-Watt Heater for Aquariums up to 65 Gal., A773
        Fluval E200 Advanced Electronic Heater, 100-Watt Heater for Aquariums up to 65 Gal., A773

          Last update on 2021-09-29 / Commissions Earned / Images from Amazon Product Advertising API

          Overall Pros and Cons

          Pros: 

          • Consistent temp
          • Easy to install
          • Simple calibration
          • Looks cool

          Cons: 

          • Exterior is glass that can crack/shatter
          • No built-in heater guard

          Conclusions

          I really like this heater and think it’s a great choice.

          The M200 is a consistent performer that did great during testing. The one I have in my 40 gallon tank has been excellent. I’ve had no trouble at all with it over the last few years.

          Overall, the more fancy, dancy Fluval E200 heater won my head-to-head challenge, but this Fluval M200 is the best old school style heater that I’ve ever used.

          It’s simple to install, use and calibrate and it’s a little workhorse that will keep chugging along for you as long as it gets proper care. Overall, it’s easy and simple to use with very few hassles.

          I hope you find this article helpful.

          I wish you and your fish the very best!

          Sale
          Fluval M200 Submersible Heater, 200-Watt Heater for Aquariums up to 65 Gal., A784
          Fluval M200 Submersible Heater, 200-Watt Heater for Aquariums up to 65 Gal., A784
            Fluval E200 Advanced Electronic Heater, 100-Watt Heater for Aquariums up to 65 Gal., A773
            Fluval E200 Advanced Electronic Heater, 100-Watt Heater for Aquariums up to 65 Gal., A773

              Last update on 2021-09-29 / Commissions Earned / Images from Amazon Product Advertising API

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              Katherine Morgan
              Hey, there! I'm Katherine from Northwest Florida. A nunchuck specialist, I've kept aquariums for over two decades, enjoy experimenting with low-tech planted setups and an avid South American cichlid enthusiast. If You'd like to see more of my tanks, check out my Instagram

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