What's the most accurate thermometer?

I currently use a digital thermometer that I purchased online. I use the same version in all three of my tanks. I heard the other day sometimes they aren't accurate. I love them because I feel like the thermometers you stick on the sides of the tank are hard to read.

That being said, what are the most accurate thermometers? I have a discus tank, so especially with the high temperature I want to ensure the readings are correct.

 

I use the Fluval Wireless Digital

 

Personally I use a combination of 3 different types. I can ensure if one fails, I have 2 others that are accurate. If you didn't want to go that route, you could see about calibration equipment. Many ways to do this. I always go the safe route. Thermometers are cheap.

 

Glass would be my opinion on most accurate. Least are the stick on ones.

 

I use glass thermometers in all my aquariums.

 

Fluke 1524-P2 Dual-Channel Reference Thermometer with 5628 prt

I actually have this one in my cart right now. It has an audible alarm.

Thermometers have to be calibrated annually. High quality glass thermometers may be an exception as they become more stable as they age but I haven't gotten a straight answer as to whether you can actually forego annual recalibration.

 

I love both of mine. I have kizen instant and copper Atkins. I don’t have thermometers in the tank I check them all the time with these meat thermometers. I had too many inaccurate and broken glass to keep that up.

 

Fluke 1524-P2 Dual-Channel Reference Thermometer with 5628 prt

I actually have this one in my cart right now. It has an audible alarm.

Thermometers have to be calibrated annually. High quality glass thermometers may be an exception as they become more stable as they age but I haven't gotten a straight answer as to whether you can actually forego annual recalibration.

That’s $6000! Wow! Maybe I need a new one.

 

I have glass thermometers in the tanks and a temp gun as well.

 

Thanks all! Looks like I am going to be buying a glass thermometer again.