I just got a tilt and am learning new things about my setup: there is a significant difference between the temp at the top of the fermenter vs the bottom. In a 3 gallon carboy in the frig, I use an inkbird with a thermowell controlling a heat wrap giving me 70 degrees towards the bottom of the carboy (for example) and the tilt at the top reads 62. Everything is calibrated so I believe the numbers. It makes sense to me that the top of the wort would read colder in a glass carboy even though I've wrapped everything in a towel. I've read a number of posts saying this thermal difference is correct. So with that in mind, should I use the temp at the top of the carboy as my fermentation temp for an ale yeast, or the temp at the bottom?