What is the Best Aquarium Heater in the UK?

What is the Best Aquarium Heater in the UK?

If you’re wondering what the best aquarium heater currently available in the UK is, you’ve come to the right website. 

Aquarium heaters do the very important job of not only increasing your aquarium’s water temperature to the optimum level for your fish but also ensuring that the temperature remains stable. Although this may seem like an obvious thing to state, the role of an aquarium heater in tropical fish tanks cannot be understated; in short, it is absolutely critical to the health and longevity of your fish. 

The question is, which aquarium heater should you buy? With so many currently available on the market, trying to decipher which model is best is a rather tricky task. Luckily for you, we know a little about keeping fish and how to choose the aquarium heater, and in today’s piece, we’re going to share our expertise with you.

Aquarium Heaters: An Introduction

The vast majority of tropical fish species thrive in water that is between 23C and 28C; however, keeping your aquarium’s water at this temperature is almost impossible without using an aquarium heater (I’ve tried, and unless you’re willing to leave your heating on 24/7 and live in 35C heat in your home, an aquarium heater is by far and away the better – and cheaper – option!). 

Keeping your aquarium’s water at a stable temperature is essential if you want your beloved fish to live a happy and healthy life, and a high-quality heater will do this task easily. If the water is too cold, your fish will become lethargic and will probably stop eating (and potentially freeze to death if it gets too cold); if the water is too hot, your fish could overheat and die a slow and painful death. Therefore, getting your hands on a high-quality aquarium heater is absolutely vital. Period.

However, knowing which to opt for isn’t – as we pointed out above – the easiest task unless you know exactly what to look for. You’ve got to take into account aquarium size, which species will live in your aquarium (and how many total fish), the location of your tank, etc., all of which can often lead to a state of confusion as to which one to actually buy! To help you buy the best aquarium heater, we’ll take you through each step bit by bit, furnishing you with all the knowledge you need to make the right decision. 

What do you need to take into consideration when buying an aquarium heater?

There are a wide array of factors that need to be taken into account when choosing a heater for your aquarium. The list below contains the main five factors and enough information on which to base your choice, but we always recommend carrying out your own research (you can never do enough research and reading, in our opinion!). So, without further ado, let’s take a look at this quintet of factors you need to think about before purchasing an aquarium heater.

#1 – Which fish species?

Factor number one is related to which species of fish you’re going to keep in your aquarium. Tropical fish, by their very nature, are very sensitive beings and, therefore, are easily affected by conditions that aren’t optimum for them. Having the temperature just right is a critical factor in promoting health and vitality, so knowing exactly what temperature your fish need is absolutely vital. If you plan on keeping more than one species, ensure that they live in similar water temperatures; otherwise, one species isn’t going to do very well. 

#2 – How big is your tank?

Size also plays a large part in heater choice – not only with brand and model but also how many heaters you’ll need. Smaller tanks will typically be OK with one heater, whereas larger tanks may require multiple heaters situated at either end of the tank to ensure an even (and optimal) temperature. 

#3 – How many heaters do you need?

As stated above, in some instances, you may need to use two heaters, I.e. if you have a large tank, but some experts suggest having two heaters regardless of aquarium size. Why? For the sake of your fish. Imagine you have one heater, and it fails; if you don’t spot this relatively quickly, it could mean curtains for your fish. Tropical fish are exceptionally susceptible to temperature changes, so keeping a consistent temperature is critical. Of course, many aquarium owners who have only ever used one heater will have never run into this issues, but it’s certainly food for thought. 

#4 – What size heater? 

It’s imperative that your heater matches the size of your tank. If it’s too small, it may not heat up the water and keep it at the optimal temperature compared to a bigger heater. Furthermore, it’s important to take into consideration the thickness of your aquarium’s glass. Thinner glass will lose heat quicker. (We’ve written a section dedicated to this question below). 

#5 – Where is your tank positioned? 

Where your tank will be positioned and which room it will be in is another important factor. Will it be in a room that’s big and warm or in a room that’s small and cold? Will it be by a window where the sun will heat it during the daytime but result in it getting colder at night? Is it near a radiator or air vent/conditioner? Everything can potentially impact your aquarium, its heat, and its ability to maintain the correct temperature, so think about the rooms and positions where is least likely to be affected. 

Ok, so now we’ve looked at the five most important things that need to be considered before purchasing an aquarium heater; let’s discuss our top five tips when it comes to selecting a heater.

Buying an Aquarium Heater – Our Top Tips

It’s important to remember that using an aquarium heater isn’t merely a case of setting it and forgetting about it. Like every single piece of equipment, heaters can fail, break, potentially overheat your aquarium, or not keep it warm enough; therefore, we highly recommend taking into consideration the following advice:

#1 – “Buy cheap, buy twice”

This cold adage is one of my favourites, and one that is certainly apt where buying electrical equipment is concerned. Purchasing the best aquarium heater you can afford is highly recommended. It’s all too easy to skimp on an aquarium heater and buy one that isn’t good enough or simply won’t last. Think about it as an investment that will save you money in the run and, more importantly, ensure that your fish live a happy and healthy life. 

#2 – Look at the instructions

I’m definitely guilty of this, and I’m sure some of your reading this are also guilty of it too! Always read the instruction for your heater before installing it. Although most heaters are the same, some may require something slightly different, so it’s worth taking ten minutes to familiarise yourself with the heater and the manufacturer’s guidelines. The instructions are there for a reason – so use them!

#3 – Use a thermometer

Yes, even if you buy a very high-quality aquarium heater, you’ll still need to keep an eye on the temperature using an in-situ thermometer, i.e. one installed inside the tank, to give you an accurate reading. Some experts suggesting having a spare installed or to hand just in case, and we think this is a wise idea as if your thermometer is faulty, it’ll be your fish that will pay the price. Luckily thermometers are expensive, so having one or two installed and spare won’t cost an arm and a leg.

#4 – Think about getting a temperature controller

If you’re away from your tank for extended periods or merely aren’t able to check it very often using a regular thermometer, temperature controllers are available that will do the job for you. This device will both monitor and control the temperature – with some models even altering you should anything need changing. Although they can be quite expensive, they’re certainly a worthwhile purchase if you’re unable to check the temperature frequently, i.e. on a daily basis.

What type of aquarium heater should you buy?

This is the all-important question! In this section, were going to look at the four main types of aquarium heaters available, explaining how they function and other information that will help you decide whether or not they’re a good option for your aquarium. So, let’s take a look at each in turn.

Submersible Aquarium Heaters

As the name suggests, submersible heaters are meant to be situated inside your aquarium, i.e. in the water. Although designs may vary, they are typically long and slender, resembling a thin tube. In most instances, they will attach to the side of the aquarium (on the inside) using suction cups and can be positioned vertically, horizontally or diagonally. One key point here is that if you have a tank with gravel as the substrate, it’s essential to keep the heater away from the gravel as gravel isn’t the best conductor of heat; this could potentially cause damage to the heater.

As this type of heater is completely submerged, it’s commonly more efficient than other types of aquarium hearer. If it has an in-built thermostat, it is best placed horizontally as this will give a more accurate reading. 

Our top picks:

Immersible Aquarium Heaters

Immersible aquarium heaters are typically a glass tube that contains a heating element wound around a glass or ceramic insert. In some cases, immersible heaters may also contain sand, and the vast majority of them are actually fully submersible. 

The other type of immersible heater commonly available are often called ‘hanging heaters’, which, as the name indicates, hang from the side (or top) of your tank but aren’t able to be 100% submerged in the water (they will typically have a water line mark on them to show you how far into the water than can be submerged). 

Our top pick:

Substrate Aquarium Heaters

Substrate or ‘cable’ heaters use a heated cable that runs under the substrate of the aquarium (typically sand or gravel), which means the heater is completely hidden (perfect for all of you who would prefer not to see a heater in your aquarium!). Of all the heater types mentioned in this article, substrate heaters are the least common. Some experts think that cable heaters are the best option for aquariums with plants as gravel tends to keep the roots of the plants cooler, which is optimal for growth. 

Our top pick:

Filter Aquarium Heaters

Some filters actually contain an in-built heater; therefore, you kill two birds with one stone (but let’s hope you don’t kill any fish, right?!). Although they are relatively rare, it’s a great choice if you don’t want pieces of equipment clogging up your tank or are only using a small tank and want your fish to have as much room as possible. 

Our top pick:

What size heater should you buy? 

Getting the right size heater for your aquarium is absolutely critical to the health and wellness of your fish. The question is, what size is the right size?

Although there is no exact rule, most experts agree that you should between 2.5 and 5 watts of heat for every gallon of water. However, a degree of flexibility is required with this guideline as larger aquariums tend to lose heat at a slower rate than smaller tanks; therefore, it’s not possible to directly compare the two.

For example, a 15-gallon tank will need between 35-85 watts, whereas a 75-gallon tank will need 250-300 watts. And tiny tanks are actually quite difficult to heat and keep the temperature stable (a lot harder than you’d think!). This does seem to defy logic given that you’d think smaller tanks would be easier to heat up and keep stable due to less water volume, but in reality, the reverse is true. 

Furthermore, the temperature of the room your aquarium will live in will also impact your choice of heater. For example, if the room is 23C and your fish need 25C, you’ll need a smaller heater than if your room is 20C and your fish need 28C water temperature. 

The Best Aquarium Heater: Final Thoughts

If you’ve made it this far, have managed to read and absorbed all of the information above, yet still aren’t sure which type of aquarium heater to choose, don’t worry! It is difficult to decide given the pros and cons of each, but to help you out, here’s how we’d rank the above four aquarium heater types in order of preference:

1) Submersible.

2) Filter heater.

3) Immersible.

4) Substrate.

Why in this order?

Well, submersible heaters are the most common, very affordable, and are generally easy to use. The vast majority of aquarium owners will opt for this type of heater because of the three previously-mentioned reasons. I’ve used submersible heaters for many years and have always got on well with them – and there’s no reason why you wouldn’t too. 

Filter heaters come in a very close second place because they’re also easy to use, kill two birds with one stone, and can often be more cost-effective than buying a separate filter and heater. However, the main downside of filter heaters is the fact that if they fail, you have to spend more replacing them, rather than if you had a separate heater and filter and one malfunctioned. I have used filter heaters in the past and do recommend them (particularly if you have a small tank and really want to maximise the space you have), so they’re definitely a viable option. 

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