# Sticker Thermometers



## Jman26

When I purchased my Aquarium it came with a Marina sticker thermometer. Ever since I have had it, the tempurature always seemed unusually high. (Yes I know how to read it) The room temperature of my house is usually 23C and this thermometer reads 26-28C. I don't use my heater in the summer due to the types of fish I have. I have a rather large filter for my tank, so I think it adds a degree or two but the temp. still seems high. I have a regular Fluorescent bulb (and no the aquarium is never in sunlight or near a vent).
So I recently buy a cheap regular aquarium thermometer and with 23C room temperature it reads 24C which is more like it. 

So the sticker thermometer wasn't reading properly right? Has anybody else had problems with them?


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## iamntbatman

Some people say they're worthless crap, but I don't mind them. Not as accurate as a regular glass thermometer, but they do have their advantages such as when you're housing big boisterous fish that might break a glass one. If anything, mine usually read a few degrees (F, not C) colder than the tank water because room temperature is lower than the tank temp.


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## Tyyrlym

Old but I figured I'd chime in.

The problem with the stick on thermometers is that the manufacturer had no idea what tank they'd be stuck on. Ambient temperature in the room, the thickness of the glass, whether or not its glass or acrylic, even what type of glass or acrylic it is are all important factors in determining the thermal conductivity of the material the thermometer is stuck to. Without that information there's no way for the manufacturer to calibrate the stick-on. So the manufacturer makes assumptions. They assume roughly what size aquarium you will have, what it will be made of, and what temp your room is likely to be. Now if your aquarium is very close to these assumptions the stick on will be spot on. The farther you get from the assumptions the worse the stick-on gets.

I'd say that if you have a tank in the 20 to 30 gallon range in a typical 72-74 degree house and its made from conventional glass or acrylic a stick on will probably do decently. Really though, a stick on cost about two bucks a much more accurate "mercury" one costs three. Just buy the "mercury" one and be done with it.


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