November 17

6 Best Small Fish Tank Heaters – Buyer’s Guide 2024


small fish tank heaters

The need for a small aquarium tank heater in your aquarium is informed by the fact that fish species do not have an internal mechanism to maintain their body temperature – they depend on the heat generated from the outside, the environment around their habitat.

However, since there is a tendency for the external temperature to fluctuate – a situation that may cause stress and endanger the health of your precious pet – it is important to incorporate a small tank heater to maintain the temperature within a constant or desired range.

But as tank heaters come in varying wattages, one would have to select a heater that will adequately serve the temperature need of his/her fish.

Factors to keep in mind while choosing a small aquarium heater

  • Firstly, using a heater with a large wattage capacity in a small tank could cause overheating thereby wreaking havoc on your tank and subjecting your aquatic pet to life-threatening burns.
  • Again, to be a bit blunt; going for a higher capacity heater is nothing but a waste of resources –money and energy [as it concerns power consumption].
  • So, you should see to it that you go for a mini heater specifically made for nano tanks; one that would evenly distribute heat within the aquarium.

In view of this, I have six of the smallest fish tank heaters laid out for you in this review. Read on to have a glimpse of them before hitting the road or navigating the web for the pet store.

6 Small Aquarium Heater Reviews 2023

1. GOOBAT Mini Fish Tank Heater

GOOBAT Mini Betta Heater


The GOOBAT Mini  1 gallon Fish tank heater is indeed a gadget designed to help keep your aquatic pet warm.

The device features an LED indicator that comes on – reflecting red light – whenever it is heating. It can be fully submerged in the water.

Specifications and Features:

  • It is available in two different sizes; the 15-W variety [for tanks measuring between 3.7 – 20.8 liters] and the 25-W variety [for tanks measuring 22.7 – 37.8 liters].
  • This small fish tank heater is made from polypropylene carbonate (PPC) plastic, a material that imposes a high degree of durability on the product.
  • This heater’s temperature is preset to 250C, and it is equipped with an inbuilt thermostat that shuts it off once the (temperature) value rises by 10

A lot of aquarists that have incorporated this GOOBAT mini fish tank heater into their aquarium set-up have affirmed that it is very functional, stating that it is quite reliable – its performance being consistent – and that it does not overheat.


  • Compact design
  • Durable
  • Very effective
  • Fully submersible
  • LED indicator


  • Temperature is preset hence, it cannot be adjusted
  • Suction cups do not always stick

2. Marina Submersible Mini Fish Tank Heater

Marina Submersible Mini Fish Tank Heater


Marina does well at making quality aquarium goods, and this small fish tank heater suitable to 5.5-gallon size is yet another of its signature.

    This Marina compact fish tank heater, built for saltwater and freshwater aquariums, can be completely immersed in water and is fitting for a 20-liter tank.

    The design also features a bumper guard which serves to keep fish from getting scalded or shocked by the heater.

    Specifications and Features:

    • It consumes 25 watts of power.
    • This Marina submersible mini fish tank heater is made from a tough glass material that ensures protection against impact and even impacts long-lastingness. Plus, it has a ceramic core to aid in advancing effectiveness.
    • It also possesses an on/off light indicator that is useful for communicating its (functioning) status upon being installed into the aquarium.
    • With the aid of a thermometer – which is not included in the package – you can set the temperature to the desired value using the grey knob at the top.
    • Suction cups are also available in the kit for its installation. It can be used to achieve a temperature of about 26.60

    There are quite a number of things that seem to thrill aquarists about the Marina submersible fish tank heater; one of these is its design which makes it possible to seamlessly fit the device into the aquarium. Apart from this, it has been said to be very dependable, and of marked quality.


    • Highly functional
    • Temperature adjustment is possible
    • Compact design
    • Easy to install and use
    • Inbuilt thermostat
    • Reasonably priced


    • Suction cups are not up to the scratch

    3. BOEESPAT Small Fish Tank Heater

    BOEESPAT Small Fish Tank Heater


    Here is another small fish tank heater built for 2-gallon aquariums and has profound technical adeptness. It is made for tanks with a maximum carrying capacity of 7.5 liters, wherein it is able to maintain the water temperature between a range of 25 280C.

    It can appreciably withstand heat as the outer casing is made from ABS and it is augmented by an MCH alumina ceramic heating system.

    To help you in deciphering its state of operation, it has been equipped with an LED indicator that shows you whether it is working optimally or not.

    Specifications and Features:

    • This one is a 20-watt capacity heater that can be wholly submerged into the water – the waterproof capacity rating is IP68.
    • The BOEESPAT small fish tank heater has an inbuilt thermostat which ensures that the device shuts off automatically once the value is 1.50C above the desired temperature.
    • It comes with two suction cups for secure attachment to the tank.
    • The dimension of the heater is 11.2 X 3.9 X 0.9cm.

    Judging by (customers’) reviews, you will perceive a feeling of gratification being expressed among aquarists that have tried out the BOEESPAT small fish tank heater. The reason for this, primarily hinged on the effectiveness of the product, and some have spoken pleasantly about the quality it reflects.


    • Highly functional
    • Inbuilt thermostat
    • Reliable
    • Easy to use
    • Equipped with LED indicator
    • Temperature can be adjusted


    • None

    4. Hygger Mini Fish Tank Heater: Suited for 3-gallon fish tank heater


    We have yet another fantastic heater in this Hygger Mini Fish Tank Heater. This very heater is also well-made; it was designed using top-quality materials and supported with features that enhance its usability.

    The Hygger mini small fish tank heater’s outer casing is of shatterproof quartz which is further equipped to offer protection against shocking and burns – so, you can be sure of the safety of your fish with this heater on hand.

    It is yet worth noting that the hygger mini fish tank heater shut off automatically once it outside the aquarium water – even while it remains plugged.

    Specifications and Features:

    • It is available in two wattage capacities: the 50-watt type for tanks measuring 3.8 – 24.6 liters and the 100-watt variety for tanks measuring 24.6 – 49.2 liters.
    • With the aid of the thermostat integrated into it, it automatically shuts off once there is a variation of +10F from the temperature that had been set beforehand.
    • In addition to the aforementioned, there is an external temperature controller that allows you to set the temperature to between 17.2 – 34.40C depending on the needs of your aquatic pet(s).
    • The waterproof capability rating of this device is IP68, and it also has an LED indicator to intimate you about its working condition, particularly as touching temperature reading.

    The reliability and effectiveness of this Hygger small fish tank heater have certainly not gone unnoticed by numerous individuals who have seen it work firsthand. In general, the product is well-regarded among customers who have been pleased with their buy.


    • Amazing quality
    • Highly efficient
    • Safe and reliable
    • Easy to install
    • Run-dry protection
    • Precise/accurate temperature
    • Temperature adjustment is feasible


    • Somewhat bulky
    • Suction cups may not stand the test of time

    5. ZEETON 25 W Small Fish Tank Heater

    ZEETON 25 W Small Fish Tank Heater


     Up next is the ZEETON 25W tank heater for a 2-gallon fish tank, a device that is notable for its outstanding functionality and ease of use. The construction is well thought-out and it is integrated with many relevant features.

    This small fish tank heater from ZEETON can be completely submerged in water and it is also highly resistant to shock and heat – this is an offshoot of the shatterproof materials used for making it.

    Specifications and Features:

    • As already communicated, it is a 25-watt heater and would be suitable for a tank of 7.6 – 20 liters. It is 13.5cm long.
    • The waterproof capacity of this product is rated IP68. It also features a stick-on thermometer strip – which is a sort of graduated scale – that makes it easy for you to set and read the temperature.
    • It can be set to a temperature range of between 250C 280C, and it is integrated with an advanced circuit board that boosts its capability to shut off automatically whenever there is a spike in the desired temperature setting.
    • A suction cup is also available to aid in securely installing the device.

    A host of customers valued the ZEETON small fish tank heater for being able to consistently maintain the desired temperature within the aquarium. It is hard to come by reports about a spate of sudden temperature swings/fluctuations with this particular piece around.


    • Highly functional
    • Inbuilt thermostat
    • Good quality
    • Easy to use
    • Energy-efficient


    • None

    6. Aqueon Mini Fish Tank Heater

    Aqueon Mini Fish Tank Heater

    Simple in design, small in size yet having the needed features that make a functional heater.

    This smallest fish tank heater is made from a plastic material that has been fortified to withstand damage from heat.

    It can be positioned at the bottom of the aquarium either in a horizontal or vertical orientation as means of the suction cup that is included in the kit.

    Specifications and Features:

    • It is a 5-watt device that is meant to be fully immersed in water to function – it has a substantial waterproof capacity.
    • It is built for tanks with a maximum carrying capacity of 9.5 liters and will be suitable for use in an acrylic or glass aquarium.
    • Just for the mention; the heater can attain a temperature of between 200C and 28.80 It has a power cord though it does not feature any control switch.

    The Aqueon mini fish tank heater is one of the very few (heaters) that would make a happy customer. This is will not sound like an overstatement upon coming across customers who ascertained that it is an excellent option [of heater] for nano tanks. They have known it to be very reliable and well-made.


    • Functional and reliable
    • Sleek design
    • Reasonably priced


    • Temperature cannot be regulated
    • Does not have an LED indicator


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