LCR Hallcrest Aquarium Thermometer Rated one of the top 5 thermometers.
This type of thermometer comes in the form of a vertical or horizontal strip that you can stick on the outside wall of the aquarium.
The advantage of getting this type of thermometer is that they’re easy to use and are pretty much unbreakable. They can show you either Celsius or Fahrenheit readings (or both!) and you have the option of placing them on an area that will not obstruct your aquarium’s aesthetics.
One of the downsides of using this, however, is that readings can be inaccurate due to the thermometer being placed outside of the aquarium. The room temperature may also affect the thermometer, so it would be advisable to stick the strip on an area away from direct sources of heat or cold, such as sunlight and air conditioner.
It is also recommended to avoid placing the thermometer below gravel level as the reading may not be as accurate as well.
The most ideal way of using the LCD thermometer is when it’s viewed straight on, as this is how it can read temperature best. This type of thermometer can be hard to read in low light and it does not come with an alert feature.