Thermometer questions

The glass thermometer is your best way to get the most accurate temperature you can get.. Though I now use a coralife digital thermometer and its pretty accurate.
Best place to place the thermometer is on the far side of the tank away from the heater.

I use glass. One on each side of the tank.

I have 10 tanks I use the glass thermometer's at the point farthest from the heater I use this High Precision Aquarium Thermometer to get the right temp and with a grease pencil but now I use a ptouch to label the difference in temps. ie +2 degrees http://www.thatpetplace.com/pet/group/11417/product.web

thermometer's vary in readings for many reasons the glass tube can and does move along the scale.
the digital ones IME have different readings an example I had 2 of the coralife ones on a 90 right side was always 2 degrees colder than the left sure enough I finally after days of trying to adjust the right side heater and pulling my hair out I switched the thermometers and that was the problem.

I then proceeded to do some reading on thermometers there are set standards but manufactures can disregard them. thus you have thermometers that can be 4+/- degrees off or more in the aquarium hobby.

The only way to get an accurate temp. is to buy a calibrated thermometer that is certified to meet the (I for get the acronym) standard.

only use those cheep thermometers as a guide to weather your heaters are working.

Thermometers in our hobby are as accurate as the test strips :wall:

Nova Tech

http://www.novatech-usa.com/Glass-SAMA-Thermometers/860FP10

I purchased this thermometer from novatech. It is a 12inch mercury/glass thermometer.
It is very accurate. I would also recommend the thermometer armor if using mercury thermometers. I might have paid $40 for the therm. armor and shipping. I chose a thermometer with a fairly small range. Thermometers that have a large range are less accurate over their entire range. This web site has many hundreds of thermometers for many applications, so finding what I wanted was a challenge. I chose the above linked thermometer for it realitivley narrow range (-30F to 125F) and partial immersion design.
This thermometer is very accurate using the ice water technique. Fill a container with ice, add water, add thermometer, wait 5 minutes. It should read 32F.

Just to note:

In my experience the Coralife Digital Thermometers are very inaccurate. I have two: one reads 12 deg F too low, and the other one reads 2 deg F too low.


I use alcohol/glass thermometers.