Digital Thermometers are NOT Accurate

[Sandeep]

I've tested a bunch of coralife, marineland and off brand digital thermometers and almost none of them are accurate. Given the amount of money you invest in your tank, getting an accurate temp readout is critical. Do yourself a favour and get one of those laboratory grade 12" mercury thermometers (like the kind used in your high-school chemistry class). They can be purchased from scientific supply stores. My mercury thermometer runs from 0F to 200F.

Use your mercury thermometer to figure out how many degrees off your digital really is and then you can still use your digital thermometer knowing full well what the calibration difference in readings should be for the temp you want. So when my digital reads 86F I know it's really a perfect 78F. In testing the various digital thermometers I found them to vary by as much as 14F which is crazy.

Don't be cooking or freezing your corals looking at that digital readout and thinking it's accurate.

 

[Amoore311]

I've got a Digital Coralife Thermometer in my Sump (1 Heater is located here). I also have a standard mercury floating thermometer in my overflow (another heater located here). I know they don't contain mercury anymore but w/e lol.

I use the standard thermometer to keep the digital one in check. They have both been spot on so far. I think the digitals tend to go wacky once the batteries start die'n.

 

[spleify]

Digital Thermometers are NOT Accurate

No they are not.

They never have been. Floating glass thermometers are the only ones I have ever trusted.

Spleify

 

[Sk8r]

Good note.

Another good precaution is to maintain your temperature in the center of the safe zone. This goes for salinity, all other parameters. Running at extremes means being one tick away from trouble.

 

[Savas]

Take all of them as +/- 2 degrees.

 

[meschaefer]

I also keep a floating glass thermometer in my over flow, in addition to the digital in my sump. I ofter compare the two, and they are always withing a degree of each other.

 

[vanmo92]

Ohh well, they are accurate enough for me.

 

[superedge88]

I use this oregon scientific indoor outdoor thermometer. You can buy them from Target. Used them for years in many different tanks both personal and maintenance accounts. http://www2.oregonscientific.com/shop/product.asp?cid=2&scid=5&pid=240

 

[flyyyguy]

most sure,.y are accurate.........the number they read just might not be.

Example....I have 4 pinpoint digital probes all reading off the same monitor. there is a 3 degree swing in between what the four of them will read sitting in water of the same temp

get a glass of ice......fill it with water and stir for 30 seconds. It shoudl read 32 degrees. note the difference and your imporper;ly calibrated thermometer is now accurate as long as you add or subtract its specific misreading