
YukiHalu Small Aquarium Submersible Heater
Super Mini Size, 25Watt for 1-5 Gallons YukiHalu 25W aquarium heater is designed for 1-5 gallons mini fish tank. Compact design, take less space in the fish tank, easy to hide in the tank. Temperature can be accurately adjusted from 64 to 93F. This heater suitable for both saltwater and freshwater. The rated voltage is 100-130V.
The YukiHalu small submersible aquarium heater is a cheap (and, frankly, ugly) heater that's perfect for keeping your fish happy and healthy in tanks ranging from 5 to 20 gallons. It turns on automatically and maintains a steady temperature, and it includes a built-in thermometer and external temperature controller. The external temperature controller is easy to use, and you can set it to display the temperature in Celsius or Fahrenheit. The heater is 25 watts, and it's small enough that you could actually tuck it under or on top of your aquarium. The heating element isn't removable, so if you need to replace the heater, you'll have to replace the whole thing, but the heater itself is still cheap enough that it isn't a huge deal. The heater includes a returnable 1-year warranty.

FREESEA 50W Mini Aquarium Heater Fish Submersible Tank Heater with LED Temperature Display
Touch button, cyclic adjust temperature , easy to use and Safety.
The FreeSea 50W Mini Aquarium Heater is an affordable, easy-to-use submersible heater that's great for tanks and aquariums. It features a built-in temperature display and an LED that makes it easy to monitor the temperature. The heater heats quickly and keeps the tank at a steady temperature, so it doesn't dip or spike. The heater also shuts off automatically when it reaches the specified temperature. The FreeSea 50W Mini Aquarium Heater is small enough to fit in a 5-gallon aquarium, so it's ideal for 10-gallon tanks. The heater is submersible only, so you'll need to use a separate water filtration system. The heater has a 12-month warranty, and it's recommended for use with aquariums up to 10 gallons.

PULACO 25W Mini Aquarium Heater with Controller External & LED Temperature Display
Easy to operate: This heater is different from traditional heaters. It is designed with an external controller for temperature display and temperature adjustment, which can freely adjust the temperature you need (68F-93F).
The PULACO 25W Mini Aquarium Heater with External Controller and LED Temperature Display is an inexpensive heater that works well in small and medium sized aquariums. It's easy and intuitive to use, and it keeps aquarium water at a steady temperature. This heater is constructed from high-quality materials, so it's sure to last. Setting the water temperature is easy, and the built-in controller is easy to operate. The heater has a 60-day warranty, so it's well worth the money. It retails for $27.99, and you can buy it here.

hygger 50W Mini Submersible Digital Display Heater Aquarium for Small Fish Tank
Compact Small Heater110-120V/60HZ oval shape design little aquarium heater, fast heating for small fish tank. 50W tank heater is for 1-6.5gallon, 100W tank heater is for 6.5-13 gallon. Heater Dimension: 2.7x1.4x 4.5 inch. The power cord is 5ft, long enough for use indoors. With 2 strong suction cups at the back side of the betta heater, it's easy to install it on to glass, acrylic or plastic tank
With its small footprint, the hygger 50W Mini Submersible Digital Display Aquarium Heater for Small Fish Tank, Compact and Fast Heating Thermostat, with External Controller and Built-in Thermometer, for Betta, Turtle is small enough to fit almost anywhere, and its heating function works efficiently and reliably. The heater features an external controller and a built-in thermometer, and the LED display makes it easy to see and set the temperature. The heater also features a quiet, energy-efficient motor, and it heats up quickly. The heater's small size also means that it's energy efficient, so it won't take as much energy as larger heaters. The heater also has a built-in thermostat that automatically turns the heater on and off as needed, so you won't have to worry about over or under heating your tank. The heater also comes with a 90-day warranty. Overall, the hygger 50W Mini Submersible Digital Display Aquarium Heater for Small Fish Tank, Compact and Fast Heating Thermostat, with External Controller and Built-in Thermometer, for Betta, Turtle is a reliable, efficient heater that's small enough to fit anywhere and will keep your fish tank water at a comfortable temperature.

YukiHalu USB Powered Aquarium Submersible Heater
Super Mini Size, 10Watt, below 1 GallonYukiHalu 10W aquarium heater is designed for the mini fish tanks less than 1 gallon. Compact design, take less space in the fish tank, easy to hide in the tank. Temperature can be accurately adjusted from 64 to 93F. The rated voltage DC 5V/2A. Important tips: insufficient power of the adapter will cause no heating. make sure the power adapter has enough power.
The YukiHalu USB submersible aquarium heater makes maintaining the temperature of a small fish or shrimp tank easy. The heater uses Intelligent Frequency Conversion Technology to maintain the temperature with an accuracy of 1. The heater stops automatically when the set temperature is reached, so you won't have to constantly adjust the temperature. The heater's external temperature controller lets you set the temperature easily, and a built-in thermometer shows you the water temperature in real time. The heater is designed to automatically shut off when the set temperature is reached, so it won't run longer than necessary. The heater is also submersible, so it won't flood your tank, and you won't have to worry about getting it wet. The heater comes with a one-year warranty, and it's designed to operate at temperatures between 50 and 86 degrees Fahrenheit.

Orlushy 100W Mini Submersible Aquarium Heater with External Controller Temp and Built-in Thermometer for Small Fish Tank
External controller: This heater is designed to be the external controller, and users can change the temperature without having to get your hands wet or without having to take the heater out of the aquarium, providing great convenience
The Orlushy 100W Mini Submersible Heater is a decent little heater for a 10-30 gallon fish tank. It's simple to operate, easy to set, and works best for tanks under 30 gallons. It heats up quickly, quickly heats water, and is small enough that it won't take up much space in the tank. The heater has a built-in thermometer, which makes it easy to control the temperature, and the heater shuts off automatically when it hits the target temperature. The 100W heater is a good choice for tanks up to 30 gallons, but for tanks larger than 30 gallons, we recommend one of our other picks.

YukiHalu Small Size Aquarium Submersible Heater
External Temperature Controller & Never Wet Your Hands Use an external controller to set the temperature instead of immersing your hands in water to rotate the dial. Never wet your hands or contaminating your tank. 3 Strong suction cups, easy to install.
The YukiHalu 50W Mini Aquarium Heater offers quiet operation, accurate temperature control, and is small enough to fit in almost any aquarium. The heater is compatible with tanks that vary in size, from 2 to 8 gallons, which helps it fit in a wider variety of tanks. The heater operates quietly, so it's suitable for both adult and baby fish. The heater includes a built-in thermometer, which displays the temperature of the water on both the actual heater and the external temperature controller. The heater's temperature control is accurate, and when the set temperature is reached, the heater automatically stops heating. The heater is powerful enough to heat most small tanks, but it won't heat larger tanks. The heater includes a built-in thermostat, which adjusts the frequency of operation to keep the water at a consistent temperature. The heater also displays a fish-friendly temperature, which helps fish stay at the healthy temperature range. The heater includes a 1-year warranty, and power adapter, manual, and cleaning brush are also included.

hygger Mini Glass Aquarium Heater Adjustable LED Digital Temperature Display Small Heater Tank for Turtle Betta Fish Bowl with Protective Guard 50W
For Fish Tank 1-6.5 Gallon50 watt aquarium heater is ideal for small fish bowls and aquariums 1 to 6.5 gallons; voltage/frequency: 110 120volt/60hertz; it is ideal for betta fish and turtle tank
The Hygger Mini Glass Aquarium Heater is an affordable, easy-to-use aquarium heater for turtle, betta, fish, and shrimp. The heater is small enough to fit inside a 4-inch aquarium, and it's fully submersible, meaning it's safe to use in any fish tank. The heater's glass outer shell is waterproof, so it won't shatter if accidentally dropped, and it's housed in an ergonomic, egg-shaped case. The heater's digital temperature display makes it easy to monitor the temperature, and it has a control range of 63-94 degrees. The heater comes with a temperature lock that prevents it from overheating, and there's an automatic shut-off function that stops the heater from overheating or burning out.

DaToo Small Aquarium Heater 50W Mini Fish Tank 50 Heater Watt Submersible with LED Temperature Display
DaToo 50W Small Aquarium Heater -- A warm water temperature can always bring happiness to the fish. They can freely play around in the water without worrying about the cold, which will make them healthier and more energetic. DaToo 50W aquarium heater, three-point temperature control system, sturdy and durable, real-time temperature display and external temperature adjustment, safe and easy to use, not only can easily create a warm underwater world for your fish, but also bring them happy.
DaToo aquarium heater is our best choice for small fish tanks. It's durable, efficient, and easy to operate. It works well on smaller aquariums, so it's an ideal option for a 10- or 20-gallon aquarium. The heater is submersible, so it's easy to use and clean. The heater's LCD display is easy to read, and the temperature can be adjusted using an external temperature controller. The heater has an automatic shut-off feature, which keeps the heater from overheating. The heater has a three-point temperature control system, which is a more accurate and sensitive temperature control system than two point systems. The heater has an anti-corrosion, anti-explosion, and anti-crack resistant design, so it's more durable than plastic heaters. The heater is easy to clean, and we recommend using distilled water or deionized water. The heater is powered by a 50W heating element, which can easily heat up a 10- or 20-gallon tank. The heater is designed for freshwater tanks, so we recommend you don't use the heater in saltwater tanks.

DaToo 10 Watt Small Aquarium Heater Mini Betta Fish Flat Tank Heater for 1 Gallon 1.5 Gallon
PTC HEATING & ONLY SUITABLE FOR FRESHWATER - Unlike conventional glass aquarium heaters, PTC has better thermal conductivity and heating rate, no explosion, no breakage. Very energy efficient and environmentally friendly. Your child can operate it easily and is very safe. This mini fish tank heater is only suitable for fresh water tanks.
The DaToo 10W Mini Aquarium Heater is one of the safest, easiest-to-use heaters we've encountered. It's small, flat, and low-profile, and it won't take up much space in your tank. The heater has a maximum output of 10 watts, so it's designed for smaller tanks (1 to 1.5 gallons), but it can still keep larger tanks at a comfortable temperature. The heater also automatically maintains constant temperature between 75 and 82 degrees, so no more fiddling with the controls. Installation is extremely simple: just plug it in, and after the water is filled in, it automatically turns on and operates on its own. The DaToo Mini Aquarium Heater is very safe, since it automatically shuts off if the water level in the tank gets too low (the temperature indicator is green when it's on), and the heater has a maximum output of 10 watts, so it's perfectly safe for use with fish.