Best Heater For Fluval Spec V: Examination of Fish Warmers

The fishes can glide through the water if they stay warm and fuzzy. But with winter, their movement tends to slow down.

And in extreme conditions, the fish can even die. So, you do need heaters to keep the fish active.

However, each aquarium requires its specific style heater. And the Fluval Spec V is one of them.

But which one’s the best heater for Fluval Spec V?

Well, to answer that question, we have written an entire blog. Here, we have included a buying guide that stores all the info you need to be aware of before buying an aquarium heater.

Besides this, we have also suggested the top 5 aquarium heaters for your Fluval Spec V. Now, to check whether they suit you, let’s have a look at what they have to offer-

Comparison Table

Product Overview

First, we have the Hydor T11702 Submersible Glass Aquarium Heater. This one beat all the other aquarium heaters and took the throne. But what are some of its best qualities?

To start off, we have to tell you that this is the most budget-friendly heater on our list. However, that doesn’t make it any shorter than all the other products. This one has so much to offer.

For instance, it’s made out of shatterproof glass. So, even if you drop the heater by mistake, it won’t shatter into a thousand pieces. So, you can say that it’s highly resistant.

Other than this, it’s also shock-resistant. That means if there’s ever an earthquake or someone shakes the aquarium a bit, the heater won’t get displaced easily. Thus your fish will be safe.

Moreover, the power size for this comes at 25 watts. There are other sizes, but for the Fluval Spec V, the 25-watt heaters are the best choice.

This is the right size that ensures that the fish and coral life stays warm. At the same time, this heater doesn’t make the aquarium too hot to live in.

Now, as for the positions, this heater can be placed both horizontally and vertically. So, you can place it anywhere in your Fluval Spec V aquarium you want.

This option gives you the freedom to choose the position. So get creative!

Additionally, the set temperature ranges from 67 to 87 F. Now; this is quite a good range. You can set your aquarium to any temperature you want if it falls within this specific range.

And as for precision, the heater has a graduated scale. So you can be precise when you set the temperature.

In short, you’ll be getting a lot of benefits from this single heater. And the best part is, it comes at a very reasonable price.


  • It’s budget-friendly
  • The glass won’t break
  • You can precisely set the temperature
  • The heater won’t get displaced easily
  • You can place it wherever you want


  • After a while, it keeps getting stuck at a certain temperature

Product Overview

Moving on to a more premium brand, we have the Cobalt Aquatics 31000 Flat Neo-Therm Heater.

Now, if you’re not in money-saving mode, then we present to you an exclusive aquarium heater. Here are the details-

And, if you head over to the Amazon page, you’ll find that this heater is quite sleek looking.

It’s ultra-thin, which makes it all the more attractive. It comes in black, which is, in our opinion, a splendid color.

So, if you want your aquarium to look a bit nice, then you can invest in this heater.

Aesthetics do matter! Other than this, the Cobalt Aquatics 31000 Heater has a reversible holster or bracket.

On top of this, the set temperature range for this heater is the highest. To be specific, the temperature range is between 66 to 96 F.

Now, this means that you’ll be able to get a higher range of temperatures to control your heater.

With the help of this, you can place the heater in either direction. Now, if you prefer the front side, you can always put it out for display.

But if you desire, then you can put the backside on. In short, you have the freedom to choose.

Now, if you’re worried about your beloved fish, then fret not; that’s because this heater has an integrated thermal protection circuit. This ensures that the fish don’t get electrocuted and die due to the heater.

Moreover, this is a thermoplastic heater. That means it’s not made out of cheap glass or plastic.

It’s made of shatterproof thermoplastic. So, this heater will not break if it touches the ground by mistake.


  • Your aquarium will look nice with this
  • You get to control it within a wide range of temperatures
  • The heater won’t break
  • It can be placed in either direction


  • When they become damaged they spike up the temperature

Product Overview

Moving on to the next product, we have the Aqueon 100106100 Submersible Heater. This one is quite the catch, and for some good reasons. Stick around to find out-

To start, we must admit that this is by far the largest heater on our list. By largest, we mean that its height is the longest. To be exact, its height is 12 inches.

That means it gets to cover a lot of ground. In other words, the whole aquarium will become warmer faster because of its great reach.

Other than this, the heater also has LED light indicators. This turns on when the heater is working.

That means if you set the heater to go to a certain temperature, it’ll take a few minutes.

During that time, the LED lights will be on. After that, the heater will automatically shut down, which will be indicated by the LED light.

Now, the most unusual thing about this heater is that it’s the only one on our list that is 50 watts of power. Don’t worry; it’ll work great with the Fluval Spec V.

But it’s mostly recommended for colder places. Let’s say you live in a place where it snows quite frequently. Those places need a higher-powered heater to keep the fish warm.


  • You can control the temperature precisely
  • You know when the heater is working
  • Can warm up the tank even when it’s cold
  • It won’t shatter


  • It’s a bit noisy

Product Overview

Next up, we have the Marina 11230 Submersible Aquarium Heater. This is yet another subversive heater, but it’s quite easy to operate.

Now, this might be a buzzkill for a lot of you out there, So have a read if it suits you-

Till now, we have looked into some heaters that have thermostats built-in. This lets you digitally know what the temperature is set to.

However, they can be quite complicated for people who are technologically behind. So, if you like to dip in your thermometer to check the temperature just to be sure, this is the one for you.

Besides this, this specific heater comes with a bracket with suction cups. So, if you want to stick the heater to your Fluval Spec V aquarium, you can do so without any issue. It’ll hold quite nicely.

Besides this, the Marina 11230 Submersible Aquarium Heater also has a bumper guard.

The guard’s job is to ensure that the fish don’t get into contact with the heater and die because of an accident.

Moreover, this heater also has an impact-resistant glass design. It’s also waterproof. So, you can rely on the heater to be quite resistant.


  • It sticks to the aquarium
  • It’s highly resistant
  • The heater won’t harm the fishes


  • You need to manually check the temperature

Product Overview

At the bottom of our list, we have the Eheim 3611090 Jager Aquarium Heater.

This heater didn’t make it into the top 4, but it still has some great features worth going over. Who knows, something just might strike your liking.

Now, if you’ve seen the comparison table, you must have noticed that the power for each heater varies.

Now, for the Fluval Spec V, you need a 25-watt heater. But if you live in a colder place, you’ll need a higher-powered heater.

Besides, if you have a bigger aquarium at home, you can also shop for that one. Moreover, the heater will turn off if the water level drops too low. This ensures the safety of the fish.

Additionally, the heater will notify you whenever it’s on. This way, you can monitor the heater from a distance.

That’s because if the heater runs long, the tank will get very hot. And the fish might not be able to survive the heat.

On top of this, the glass is made of shock-resistant and shatterproof glass. So, the heater will not break easily and will be quite durable.


  • Fishes won’t be harmed by excessive heat
  • It’s durable
  • You can monitor the heater from afar


  • After a while, the temperature doesn’t adjust properly.


Buying Guide

Woah, that was one big roller coaster. But because of all the endless info about the different heaters, you must feel a bit overwhelmed. What to buy? Which one will be the best?

To figure all that out, you need to know the basics.

They will set the base so that you know that you have the bare minimum and that, later, you can choose the right one for yourself.

Types of Aquarium Heater

So, to start off, we have to discuss the types of aquarium heaters available in the market.

Now, generally, there are two types of heaters. The number on is the hang-on. The other one is the subversive one.

As the name suggests, the hang-on is the ones that stay hanging in the aquarium. They warm up the water from the outside. However, because of its outward reach, it isn’t too efficient.

For the hang-on to work properly, they need more power. And that means more energy conversion.

On the other hand, the subversive pens get to work at a close range. Thus they save you a lot of energy, and they can keep the fish warm more efficiently.

The best thing is all the heaters in our list are subversive. So, you can pick any.

Size of the Aquarium

Another thing to be aware of is the aquarium size. This will vary because the aquariums come in different sizes. But your Fluval Spec V has one particular size.

And that’s 5 gallons. So you don’t have to worry about varying sizes.

However, if you buy the heater for another aquarium, you should note that the size of the aquarium will affect the perfect heater in your case.

Besides, the Fluval Spec V aquarium is quite small. So, don’t worry; you won’t need a huge heater to ensure the entire aquarium stays warm.

Size of the Heater

Moving on, you should be aware of the size of the heater. By size, we mean power. And that’s expressed in Watt.

So, the basic rule of an aquarium heater is that they need 4 to 5 watts of power for every gallon of water.

Since you are looking for a Fluval Spec v aquarium heater, you need to buy a heater with 25 watts.

Now, most of the heaters on our list have 25 watts power range. So, pick any to suit your aquarium,

Surrounding Temperature

One more thing that plays a big role in all this is the surrounding temperature. You see, if you live in a cold place but want your fish to stay warm, you need more power.

Now, we know that we’ve said that the 25-watt heaters will work fine on Fluval Spec V, but you need to be mindful of the surrounding temperature. Let’s say that it snows where you stay.

Then you might have to buy a heater that serves 50 watts. They are more powerful and can keep your fish warmer more efficiently.

Placement Styles of The Heater

Lastly, check out whether your heater can be placed both vertically and horizontally.

Now, we have to admit that this is not a necessary criterion. However, it’s a feature that’s quite handy to have.

You see, if you can play them however you want, you’ll be able to place it at your desired location.

Now, every reefer likes to decorate their aquarium. So, having the freedom to place the heater you want will be a great option.


Question: Where should the heater be placed in the aquarium?

Answer: The perfect place for an aquarium heater is near the filter or air pump.

This ensures that the heat gets evenly distributed throughout the aquarium. The fishes get to enjoy the warmth no matter where they travel.

Question: Do you leave a fish tank heater on all the time?

Answer: Yes, you can leave the fish tank heater on all day long. However, ensure that the heater has a built-in thermostat. That can switch off the heater when they warm the aquarium to a certain temperature.

Question: Can fish get burned by a heater?

Answer: Although it’s very rare, fish can get burned by a heater. This happens when they get stuck between the glass and the heater.

Question: Can fish die if the water is too cold?

Answer: Fishes tend to die if the water gets too cold for them. The smaller fishes are more affected by this. And if the drop in temperature is sudden, the chances of the fish dying are higher.

To Sum Up

Well, in short, buy the right-sized heater, and you can place them anywhere you want.

Well, that was all we had on the best heater for Fluval Spec V. But if you still have doubts, ask us all your questions.