my digital thermometer changes throughout the day

[genocidex]

So i have both an analog (fluid) thermometer and a digital in my shrimp tank the digital is claiming a 2.2 degrees f sway from when the lights are on during the day and at night ie. 76.6 now and 78.8 when the lights are on. Is it possible since the probe is black its getting heated by my light and causing this sway? The analog one doesnt seem to change but its very small so its possible i didnt notice it. If the water is truely swaying 2 degrees during the day is that bad? Just for my shrimp wanted to keep the water close to 78.8 as i could. As its close to 80 thats was recommended for faster shrimp growth. But it seems high to me so im shooting just low of it. Also my appt doesnt go abpve 72 so its not that.

[Lady Hobbs]

Not unusual at all for lights to change temps like this. 2 degrees is nothing to worry about.

[pjaldave]

If it was 2 degrees celsius then i would be worried. temp swing like that is nothing to worry about and i think it's naturally occurring in the wild as well.

[dbosman]

Native waters warm during the day and cool at night.

Digital thermometers, unless they are expensive calibrated lab units, are not precise and should not be counted on for anything other than "close enough". That includes most digital home fever thermometers. Even for those, close enough is good enough to detect rising or falling fevers. *Read the packaging all the way through sometime. Gak!

[genocidex]

*Read the packaging all the way through sometime. Gak!

if you are implying that i didnt read the package, then yes i didnt read it because it didnt come with one. the thermometer i have was a freebee from a friend no package with it...