Actually they do put off a very particular heat signature.. Its not just the grow room they look for. My wife brother works for the okc police dept and he is the thermal FLIR operator. How do you think they find crops in the woods? You think they just spot them with there eyes?? He has no idea i even use cannabis and he never will, but he shares his stories all the time and we had a disscussion on hiow he finds it. Belive or not they acutally use the plants heat not the light...As far as the bucket is concerned u line the inside of the bucket..