Thermometers?

[TrashmanNYC]

ive been having some issues with my tank temp..........i have a coral life digital thermometer.....the water felt really warm to the touch so i checked it with an old style glass aquarium thermomter and it read 80* while my regular digital thermometer read a little over 75*.........i thought the digtal was off so i lowered my heater......a few hours later i checked it again.....the water definately felt cooler to the touch but both thermometers read almost exactly the same as before.........
any suggestions?

Thanks,
Robb

[AlishanAS]

I don't think many of the thermometers out there, especially the alcohol filled types, are very accurate. The tube may also loosen over time and slide up/down the temp scale. In one tank I placed three different thermometers and got three different readings ranging from 75 to 82 degreesF. Quite a difference.
The same can be said for the stick on types. I basically use them to see if they are within a certain range.
I cannot comment on the accuracy claims of the digital thermometers since I have never used one. Perhaps another member can comment on that type of detector.
At my job we calibrate all our temperature sensors, guages, RTDs, etc every 6 months to ensure they are within a certain tolerance. Obviously the home aquarist is not able to perform such an activity so we have to make due to with what is out there.

[foamerdave]

I don't even bother with temp guages I just use the good old dose it feel right to me way. That and all I use is steath heaters that have a temp makings on them and they seem to hold close to true

[jerrytheplater]

You can buy a good glass mercury thermometer and use that as your standard. It should not vary over time, at least as far as I know. Tom, your input needed.

[emartin]

I never buy the same brand of thermometer anywhere. I have several different brands and if I doubt the accuracy of one I just pull a glass or digital one from another tank and compare it with that.

So far, all my thermometers appear to be 100% accurate except for one coralife digital one that recently after 2 years of use is now 3 degrees colder than what any of my glass thermometers read.

Personally my favorite thermometer is one I have in my 120g colony breeding tank... I have NO idea what brand it is (unfortunately, because I want to buy more now), but it is plastic, large, with a blue liquid versus the red alcohol or whatever it is... Plus the plastic magnifies the numbers more too making it easier to read. I'm going to pull it out in another day and see if it says what brand it is.... So far I haven't been able to find it online though.

Anyway what I would do is what I am doing, just buy different random brands and if you doubt one, check it with another....or buy a high precision one (usually made for medical use I believe) or buy a professional digital one...

Hope that helps.

~Ed

[TrashmanNYC]

So far, all my thermometers appear to be 100% accurate except for one coralife digital one that recently after 2 years of use is now 3 degrees colder than what any of my glass thermometers read.


yeah, mine seems to read about 5* colder...its about a year old......

[chris1932]

My Coralife Digital will read wrong when the battery is dying.