I love the little digital thermometers. Hide a probe behind some plants, digital readout on the side of the tank, etc. They're great. But, are they accurate?
I did an experiment last night. 2 different digital thermometers, and a standard mercury style thermometer, all sensing from the same corner of one of my tanks. My temperatures read:
73.9 (digital 1)
75.3 (digital 2)
~77 (regular thermometer)
Which one is correct?
I fully understand that in the big picture of things, it doesn't matter that much. What matters is that the same thermometer I use to determine tank temp is the same thermometer I use to determine the temp of the PWC
water. I get that.
I also get that there's some accuracy tolerances on the digital thermometers as well. But this range is just too extreme IMO
. I've always held in my head that the mercury thermometer was gold, and biased my digitals to that. But i don't understand why my spread is so high. A degree I can almost buy in to, + or - (which is really a 2 degree accuracy). One of these digitals was a few bucks, one was 20 (the more expensive one is the lowest temperature, furthest away from the mercury). Obviously, there's nothing proving the mercury thermometer is accurate either, though, but irregardless they should all have been closer I thought.
Strange that the digitals don't come with a calibration on them, however.
All of my tanks in my basement are planted community tanks, so I attempt to keep all of them at the same temperature. This eases the PWC
process, using my python I drain all the tanks, then set the water temp once and refill all 3 back to back. In my basement I have a 125g, a 29g, and a 20g, and soon to add a 2.5g (although I obviously won't be using the python for that little guy).
Ok, so this was more of a rant than a question, I realize that. Thanks for entertaining me. It's funny the stupid little things that bug us sometimes, isn't it?