I heard that to get an accurate reading of the temp. the thermometer shouldn't be in any kind of direct light. Is this true? I have 2 thermometers in my grow box right now and they both read a different temp. one I have is at the top of the grow box where the tallest part of my plant is, and the 2nd one is ontop of my bubble bucket. the low one reads 79 and the top one reads 85. I think the one at the top of the grow box reads higher temps cuz its in direct light while the bottom one is shaded by leaves. So which of these is a more accurate temp???