Accurate Thermometer

  1. H

    HuliJing New Member Member

    I've used 4 different thermometers in my tank and all are giving drastically different temps. I first used a digital one that was way off, saying the water was 81 when I didn't even have a heater in it. I now have a heater and 3 alcohol thermometers. I did the ice test on all 3 too to make sure they're accurate. The one that was the most accurate is currently reading 71. The one that was 6 degrees too high is reading 87 and the one that was 7 degrees too high is reading 86. I have no clue which one to believe, it's incredibly frustrating. I'm willing to pay some good money for a thermometer that actually works if you guys have suggestions.
  2. jhigg008

    jhigg008 Well Known Member Member

    How big is you tank? I just use the cheapo mercury ones (i guess...although I dont know that they actually use mercury anymore...not sure) from walmart's fish department. I have used it in conjunction with a digital thermometer to confirm. Normally they were within 1 degree of each other or so. Have you let them all sit in there for half an hour or so just to make sure they are able to settle on an accurate read? Not sure what would be going on. I could be harder to read the temp without a heater because it might be susceptible to more rapid fluctuations in temperature, but I would not at all expect such drastic differences.

    I am not sure I know of the ice test. What exactly is that?
  3. OP

    HuliJing New Member Member

    It's a 20 gallon tank. They've been in the tank for days. The ice test I was referring to is to put the thermometer in ice water and it should read about 32 to 33 degrees. That should tell you how accurate it is to some extent.