That's why you see all the digital thermometer/hygrometers have probes on them. So you can hang it by your canopy. If you don't have a probe put it on the rim of your pots and when your plants start getting tall check the temps by holding it at canopy level every once and a while. Your plants need to be at 78 degrees. Not the floor or the wall.how do you measure canopy temps? do you hang the temperature monitor to where the canopy is? i always thought that you were suppose to keep the monitor from the lights. i have mine on the floor right next to the pot.. i been placing it at the wrong spot huh?