Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
Yes. Water temperature affects fish growth by changing body temperature, appetite and metabolism. Growth often improves as water warms toward a species- and life-stage-specific optimum, then falls when it gets too warm. There is no single best temperature for all fish, so use a reliable target for your fish rather than raising the temperature to encourage growth.
How temperature changes fish growth
Fish are ectothermic: their body temperature changes with the surrounding water. The Food and Agriculture Organization (FAO) explains that fish growth and activity depend on body temperature. Temperature also influences food intake and metabolic rate, which affect how much energy remains for growth after basic maintenance needs are met.
In a suitable temperature range, a fish may eat enough to use some of its food energy for growth. At colder temperatures, appetite and growth can slow. As temperature rises beyond the fish’s optimum, performance can decline rather than improve. The FAO describes the optimal range as one in which metabolic rates and the likelihood of eating beyond maintenance needs are high: FAO fisheries guidance on fish growth.
Why there is no universal best temperature
Each species has its own preferred range, growth optimum and upper and lower tolerance limits. These ranges can also vary with life stage. A temperature that supports good growth in one species—or in juvenile fish—may not suit another species or adult fish.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
#1 Best Overall
QZQ Fish Tank Thermometer Aquarium Thermometer Wireless Touch Stick Digital Aquarium Thermometer LED Display ±1°F for Monitoring The Fish Tank Aquarium Temperature Accessories (Black)
- New digital aquarium thermometer: LED display fish tank thermometer with professional LCD visual effect, the fish tank and aquarium water temperature can be displayed clearly, despite the night light, and can be easily read. Mini compact body design is suitable for a variety of different types of fish tanks and aquariums, is a must have fish tank accessories.
- Safe wireless touch design: The digital fish tank thermometer comes with a touch power button, which can be easily awakened by clicking. The built-in high sensor probe measures the water temperature for fish tank, well-organized wire in the fish tank to protect the fish from being swallowed or electrocuted, providing a clean and safe living environment for the pet fish axolotl turtle.
- Simple installation: The tank thermometer does not need any installation tool to remove the adhesive on the back, stick it on the outside of the tank below the tank water level, and after standing for 5 minutes, it can accurately and real-time monitor the aquarium temperature change.
- Accurate data: tank thermometer aquarium measurement range of the tank thermometer is 0°C~60°C, the accuracy is 0.18°C, and the error is ±1 °C. This is suitable for axolotl tank, turtle thermometer, saltwater fish tank accessories, betta fish tank thermometer, etc..
- Long life battery: Thermometer for aquarium fish tank is powered by a CR2032 battery (included), and the battery lasts up to 12 months. The wireless aquarium digital thermometer will automatically enter the sleep mode after 5 seconds of no operation, extend the battery life, and be more environmentally friendly and energy saving.
The best temperature can depend on what is being measured, too. The temperature that maximizes growth may differ from the one that optimizes feed conversion or survival. For that reason, do not use a published number for another species as a target for your fish. FAO guidance describes species-specific temperature ranges and explains that low temperatures can reduce food intake and growth in juvenile and adult fish: FAO training guidance on fish temperature.
What studies show about different fish
These examples illustrate why growth responses are species-specific. They are experimental results, not general aquarium temperature recommendations.
Quick Recap
Bestseller No. 3
Bestseller No. 5
Best Value
Yacumama Digital Water Thermometer for Liquids, Long Probe
- WATERPROOF - IPX7 waterproof. No worry on the rinse or wash under running water after measuring, easy clean and keep your digital food thermometer always in good shape!
- INSTANT READ AND ACCURATE - Meat thermometer instant read technology saves waiting time and gives you the accurate results. Wide temperature range from -58°F ~ +572°F with accuracy ±1.8°F.
- EASY TO USE - Power on and start measuring. Celsius and Fahrenheit could be switched anytime. Hold the result then read with no hurry. Auto power-off within ten minutes, energy saving and longer battery life.
- LONG PROBE AND ROBUST DESIGN - Long probe cooking thermometer for meat keeps you away from heat source. Step-down with food grade stainless steel material. Robust design with high standard reliability test.
- SATISFACTION USE - LIFETIME WARRANTY with 100% money back within 30 days! A good gift for kitchen beginner or master chef! Battery INCLUDED!
Rank #4
DaToo Aquarium Thermometer with Large LCD Display Fahrenheit/Celsius(℉/℃) Fish Tank Thermometer for Aquarium Reptile Terrarium Digital Water Thermometer with Suction Cup
- 【DaToo Aquarium Thermometer】: Make sure your aquarium world temperature is always as you want it to be! This water thermometer measures temperature accurately and ensures that your aquarium world is always at the ideal temperature. With its easy-to-read design, simple and easy to use operation and simple installation process, it is suitable for a wide range of aquarium environments, keep your aquarium companions in the most suitable environment for healthy growth.
- 【Accurate Measurement】: DaToo fish tank thermometer adopts a high-precision stainless steel sensing probe to ensure that the measurement error is no more than ±1℃, with a wide temperature measurement range covering -58℉ to 158℉ (-50℃ to 70℃). Which provides accurate water temperature data whether it's a freshwater aquarium, a saltwater aquarium, or a reptile breeding environment, helps you easily control the temperature changes in your aquarium or reptile environment.
- 【Easy To Read】: DaToo digital thermometer is equipped with a large LCD display, which presents the water temperature data in clear fonts, which is easy to read at a glance and greatly improves the readability. In addition, water thermometer temperature supports the free conversion of ℉/℃ units to meet your personalized preference. You can instantly get accurate temperature information day or night, creating an ideal environment for your aquarium creatures to grow and ensure their healthy growth.
- 【Simple To Use】: DaToo reptile thermometer are extremely easy to use, just gently place the probe into the water and start measuring the temperature. The one-touch on/off design saves power and is efficient as it can be easily turned off by long-pressing the power button for 3 seconds.The strong suction cup design ensures that the probe is firmly attached to the wall of the aquarium, which not only ensures accurate temperature measurement, but also prevents it from falling.
- 【Easy Installation & One Year Warranty】: The DaToo aquarium thermometer is extremely easy to install and can be fixed in just a few seconds. We've also included durable button batteries that work right out of the box, so there's no need to purchase additional batteries, making it even more convenient for you. In addition, we provide one year warranty and 24 hours professional customer service. Buy with confidence!
Rank #3
AQUANEAT Aquarium Thermometer, Fish Tank Thermometer, Digital Temperature Test, with Large LCD Display (1 Pack)
- Wide application: Ideal for use in water or high moisture environment like aquarium terrarium, or vivarium; suitable for different water types such as fresh water, tap water, salty water, marine water and etc.
- Easy to read: Comes with a large LCD display that is easy to read clearly. Thermometer size: 2.3" (L) x 1.5" (W)
- Easy to setup: Submerge probe with suction cup can easily be set in water (Submerge probe only, do not submerge thermometer in water) ; Press ''PWR'' for 3 seconds to power off
- Free Battery: 1 PC LR44 button cell battery for each thermometer.
- Wide temperature range: Measure -58°F to +158°F (-50°C to +70°C) with accuracy +/- 1°C
Rank #2
PAIZOO Aquarium Thermometer Digital, Highly Accurate Fish Tank Thermometer
- HD LED Display: PAIZOO Aquarium Thermometer adopts LED screen to display temperature, LED can provide wide viewing angle and the color is saturated, it is easier to read the data no matter day or night. Green environmental protection and energy saving
- Cordless & Touch Design: Stick-on Induction Thermometer senses water temperature through probe, cordless design, no messy wires in the water, providing a clean and safe environment for fish.Touch the button to display the temperature, and the thermometer outside aquarium will enter the sleep state after 5s
- High Accurate Display: Tank Thermometer Aquarium just needs to tear off the adhesive and stick it below the water level on the outside of the tank. The thermometer for terrarium has a reading range of 0-140 °F and is accurate to 0.9 °F. Up to 5s refresh speed allows the naked eye to detect temperature changes more quickly
- Long Battery Life: The fish tank thermometer built-in 3V battery button, the battery is long-lasting. Mini design, easy to use. Digital thermometer is suitable for different water types such as fresh water, tap water, salt water, sea water, etc., to provide the most comfortable water environment for your beloved pets
- 100% Satisfied Customer Service: We provide 12-month warranty. In the event of any product quality defects within the warranty period, we will offer a free replacement without charge. PAIZOO customer service team operates 24/7 to deliver comprehensive, hassle-free support for an optimal user experience
| Fish and source | Reported result | What the result means |
|---|---|---|
| Juvenile Black Sea flounder; 84-day trial reported in the Turkish Journal of Veterinary & Animal Sciences (2012) | Fish were tested at 13, 17, 21 and 25 °C. Growth was highest at 21 °C; estimated optima were 20.9 °C for growth and 20.2 °C for feed conversion. | The optimum differed slightly depending on whether the outcome was growth or feed conversion. Study details. |
| Lake Sturgeon; North American Journal of Aquaculture (2019) | Specific growth rates at 12.0, 17.0, 21.6 and 26.8 °C were 0.50, 1.42, 2.01 and 1.75 mm/day, respectively. | Growth rose across the lower tested temperatures, then was lower at the warmest tested temperature than at 21.6 °C. Study details. |
| Rohu carp; Aquaculture Reports (2024) | Among the tested treatments, best growth and survival occurred at 30 °C, while the lowest growth and survival occurred at 34 °C. The study reports optimal production performance around 28–30 °C under its conditions. | The reported range applies to that experiment and its conditions; it is not a target for unrelated fish. Study details. |
| Chinook salmon parr; Alaska Department of Fish and Game summary (2001) | Cited growth increased from 10.0 to 15.7 °C and decreased above 15.7 °C. | The pattern shows growth rising toward an optimum and falling beyond it. Department summary. |
How to choose and manage a temperature
- Measure the water. Use an aquarium thermometer to check the actual water temperature; do not rely only on a heater’s dial or the room temperature.
- Check a species-specific reference. Compare your reading with reliable care guidance for the exact species and life stage. Make sure the recommendation matches your goal: growth, feeding, feed conversion or general welfare.
- Make changes gradually. Avoid abrupt temperature shifts. If adjustment is needed, change the temperature slowly and monitor the fish’s response.
- Watch oxygen and feeding. Temperature changes affect oxygen demand as well as appetite. Monitor dissolved oxygen where possible and observe whether the fish are eating normally.
- Use temperature-control equipment appropriately. A thermostatic heater or controller can help maintain a chosen range, but the target must come from species-specific husbandry guidance. Check that the thermometer or controller probe measures representative water, not a misleading spot near the heater.
What to avoid
- Do not assume warmer water always means faster growth; growth can decline above the optimum.
- Do not transfer a temperature reported for flounder, sturgeon, Rohu or salmon to an unrelated aquarium fish.
- Do not chase a growth target without considering life stage, feeding, oxygen and temperature stability.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
