10 Best Inline Aquarium Heater
Updated on: May 2023
Best Inline Aquarium Heater in 2023
Hydor ETH 300 In-Line External Aquarium Heater, 300w, 5/8" hose
ISTA I-H616 500W Inline External Heater

- Power: 500W
- 2 temperature sensors, two sensors to exam the temperatures of water (Inlet and outlet)
- Thermal spraying glass, faster heating process
- External design, easy to install and does not occupy space in the Tank
- Displayed in Celsius
AKL Aquarium 500W/300W Adjustable External Inline Heater Fish Tank Canister Filter Tank Fish LED Display Overheating Protection Adjustable 12.2"X 2"X 3.5",500w

- [Temperature Range]: Precise temperature adjustment from 68℉ to 93℉.
- [LED Display Design]: external electronic theromstat, it has LED display that clearly shows you the temperature setting in either Celsius.
- [Over-temperature protection]: When the water temperature exceeds 34 °C, stop heating and prevent boiling fish.keeping you pet fish stay in a healthy and safety environment.
- [Intelligent temperature sensing]: dual temperature probe, accurate temperature control.
- [HIGH QUALITY]: The shell is made of high temperature resistant ABS material without deformation,no softening,and internal ceramic heating body, which effectively prevents damage caused by fish and turtles.
Cobalt Aquatics Flat Neo-Therm Heater with Adjustable Thermostat (Fully-Submersible, Shatterproof Design) from 25W to 300W

- Super-flat design. Fully submersible, modern design for energy efficient Aquarium and terrarium heating. Includes reversible holster/bracket, which allows heater to face inward or outward. See the product images to determine the best neo-therm size for your tank.
- Accurate, one-touch system. Simply set temperature between 66-96°f with one touch and the neo-therm electronic thermostat will maintain Tank temperature within +0.5°F. Led displays both set temp and actual temp, simultaneously.
- Ultimate safety and reliability. Integrated thermal protection circuitry prevents heater from overheating. If you forget to turn it off, the neo-therm will automatically shut it down.
- Virtually indestructible. Unlike cheap, glass heaters, the neo-therm is a resin/thermoplastic heater with a shatterproof outer-casing. Made in Poland and includes a 3-year warranty.
- Manufacturer You can trust. Most manufacturers rate their heaters on the ability to raise an aquarium 2-3°f above ambient temperatures. This is unreliable and misleading, as the average home fluctuates 2-3°f or more throughout the day. Cobalt rates The neo-therm on the ability to raise a tank 11°f above ambient temperatures, so you will never have to worry about overworking the neo-therm or it keeping up!
Feileng 200W/500W External Aquarium Heater Inline Canister Filter Tank Fish LCD Display Overheating Protection Adjustable 12"x 2"x 3.5"

- Voltage: 220-240V 50Hz,Adjustable temperature:between 20 to 35 degree
- The External Heater is completely safe and UL Listed.
- The External Heater must be used in a vertical manner for correct operation. The most common application is for use with canister filter, however the ISTA External Heater is easily adapted for use in almost any situation where heated aquarium water is required, such as with wet/dry sump pumps.
- Note: Please connect the heater on the ourflow tube of the filter bucket Direction of the arrow on the heater should be same with the direction of water flo
- There is no danger of damage if the External Heater is left running dry for short periods as the External Heater will switch itself off in that event. The External Heater heats with high efficiency by means of an internal heat pump system that avoids temperature variations. For use in freshwater and marine aquariums. Fits most canister filters.re.
AKL Aquarium External Heater in-Line Fish Tank External Heater 500W/300W Adjustable External Inline Heater for Canister Filter,500w

- [Temperature Range]: Precise temperature adjustment from 68℉ to 93℉.
- [LED Display Design]: external electronic theromstat, it has LED display that clearly shows you the temperature setting in either Celsius.
- [Over-temperature protection]: When the water temperature exceeds 34 °C, stop heating and prevent boiling fish.keeping you pet fish stay in a healthy and safety environment.
- [Intelligent temperature sensing]: dual temperature probe, accurate temperature control.
- [HIGH QUALITY]: The shell is made of high temperature resistant ABS material without deformation,no softening,and internal ceramic heating body, which effectively prevents damage caused by fish and turtles.
DaToo Aquarium External Heater in-Line Fish Tank External Heater 300W for Canister Filter

- Perfect Aquarium External Heater For Your Needs: For every hobbyist or professional fish breeder with a canister filter, a perfect external heater is essential. DaToo Aquarium External Heater is specially designed for canister filter. Leading temperature control system, precise overheat protection, provides a warm, safe and comfortable living environment for your beloved fish!
- Leading Temperature Control System: For the health of fish, a precise and constant temperature is very important. DaToo Heater's temperature control system uses advanced STM8 chip, which ensures that DaToo has a precise and perfect temperature control over the 68 ℉ to 95 ℉ range. Just set the temperature that you need, DaToo will create a comfortable environment for your beloved fish. Very Easy! Clear and large LED display, only need a light glance, you can know the current water temperature.
- Safe Over-Heat Protection: DaToo Aquarium External Heater has two temperature sensors, one at the heater inlet and the other at the outlet. This makes DaToo heater can be more accurate to measure temperature change. When the temperature exceeds the set temperature by 0.2 ℉, the heater immediately stops heating, the maximum to protect the safety of the lovely fish.
- Replaceable Inlet And Outlet: For different Canister Filter needs, we have prepared three different sizes of inlet and outlet heads in the box, 1/2" (12mm), 5/8" (16mm) and 20mm. You can choose a appropriate head as needed. A cleaning brush is also in the box and you can use it to clean the inside of the heater. DaToo has prepared everything for you. No extra purchases, save your money!
- Sturdy & Durable & One Year Warranty: Heating tube is made of German imported glass-ceramic, which is explosion-proof, shatterproof and very durable. The shell of the DaToo Aquarium External Heater is made of super-strong ABS plastic, which makes it unafraid of any external forces, nearly indestructible. The service life is 1.5 times that of similar products. One Year Warranty and 100% Money-back Guarantee, let you rest assured to choose our products. JUST DO IT, Let’t Go!!
Hygger 50W Mini Inline Quartz Glass Aquarium Heater with External Controller, Adjustable Submersible Betta Fish Tank Thermostat for 5-15 Gallon

- 🐠 【For Fish Tank 5-15 gallon】50W aquarium heater, voltage AC110-120V 60HZ, power cord is 4.6ft. Heater rod length is 5 inch, mini compact heater for small fish tank use. Perfect for betta tank. A very compact heater, easy to hide in the tank
- 🐠【Automatic Stop & Restart】Effectively maintain the tank water in the constant temp you set, stop heating when water temp reaches to the set temp and restart heating when the water temp is 1-2℉ below the set temp.The indicator light on the controller will be on red when it's heating, will be off when it stop heating
- 🐠【With Built-in Thermometer】you can set the the temp from 68℉ to 90℉,temp exactness is within 2 degrees in fahrenheit. There is a built-in thermometer in the heater to detect the water temp, not need to buy seperate thermometer
- 🐠【Durable Quartz Glass】this aquarium heater tube is heat-resistant quartz glass made, excellent in explosion-proof, can be used in fresh water and salt water aquariums, white alundum sand as the heat-conducting media, service life can be 3 years or more
- 🐠【Fully Submersible】this fish tank heater is waterproof, must be fully submerged in water when working, place it horizontally or vertically near the water intake or where the way of water flow
Hygger 500W Digital Quartz Aquarium Heater for Fresh-Water and Salt-Water, with External IC Thermostat Controller and Thermometer, Fast Heating Submersible Thermostat for Fish Tank 60-120 Gallon

- 🐠【Fast Heating Up】voltage 110-120V/60HZ, power 500W, US three-pin plug, heater rod length 10.5 inch, 500W submersible heater for fish tank 60-120 Gallon. The heater power cord is 6ft, the controller power cord is 5ft, the thermometer cord is 4.6ft. Temp range: 61-90℉. Fast heating up aquarium heater, it takes about 3 minutes to heat 3.5 gallon water up 3℉
- 🐠【Fully Automatic Control】very easy and reliable to use. After finishing the temperature setting, the fish tank heater will run automatically by itself. It will stop heating when the water temp reaches to the set temp, please note that the water temp may go up 1℉ more because of the waste heat. When the water temp is cool down to 1℉ less than the set temp, the tank heater will restart heating
- 🐠【Quartz Tube & Plastic Guard】With high-quality quartz glass tube, it's very durable and explosion-proof, this fish tank heater can be used for saltwater and freshwater aquariums, service life can be 3 years or more. With low profile black plastic guard, easy to hide in the tank. The guard can prevent your aquarium pets from burned, the gaps on the guard is about 3mm, no worries for fish stuck
- 🐠【Digital LED Display Controller】the external IC temp controller can show the water temp with 2 blue LED digits. Only show Fahrenheit degrees. To set the temp, just press the button over and over until the screen displaying the temp you desired, then stop and wait the digit flashing for 3 times, the setting is done and the led shows the current water temp again. The controller is connect with separate sensitive thermometer
- 🐠【Fully submersible Aquarium Heater】with strong suction cups on the heater guard and the thermometer, it's easy to install the aquarium heater no to the tank walls or bottom, please keep them fully submerged. The thermometer should be away from the heater and keep water circulation as far as possible
Fluval M 200-Watt Submersible Heater

- Built in reflective technology mirrors the surrounding colors, making the heater blend into your aquarium environment
- Shock resistant Borosilicate glass; High density ceramic heat sick
- Slim profile tube for easy placement; Easy to install
- Exceptional performance and unsurpassed reliability
- Suitable for aquariums up to 65 gallons; 200 watts; 3 year warranty
Aquarium Fish Food Tips
Having a balanced diet for your fish is just like having a good diet for any pet that you may have. Some people do not realize that the commercial fish food that you can buy at regular stores such as, Wal-mart, are anything but balanced.
You will also discover that foods bought at places like this are kept in big containers. The premise of the idea is to try to save you money. Realistically, a dry fish food which is what is consumed by most tropical fish, only has a shelf life of about three months. So when you are purchasing the food, you will want to buy it in smaller quantities. The people at the store are there to assist you, but you should not only rely on their recommendations because some of them are not knowledgeable about the types of food every fish needs.
The best recommendation is to first start at an aquarium shop.
When you are purchasing flake foods you are going to want to buy the one that has the most specialty-type flakes versus the ones that are cheaper. There are a few of the more popular brands that offer this type of flake food and you get what you pay for.
If you need to get freeze dried food then you are going to want to stick with blood worms or tube worms because even though they are not a complete nutrition amongst itself, it can be combined with the flake food to offer the best diet. The good thing about the tube worms is that they are a favorite among most tropical fish and come in the form of a cube. The cube can be placed on the side of the tank and the fish will just pick off what they need till they are full and since it is a non-pollutant type food, you do not have to remove it. This is a good food that you could use as a feeder for if you are gone for a few days.
If you happen to have live plants in your tank, you also have to feed them as well, so make sure that you are purchasing food for the live plants.
Another weekend feeding treat for when you are going to be gone, is to take a slice of cucumber and attach it to an aquarium friendly rock with a rubber band. This will feed your fish for quite a few days and it is not a dietary supplement, but more like a treat that still provides some essential vitamins to the diet of your fish.