they do give off a nice glow. but i would be hesitant to cut holes in roof. i have seenbottles and such inserted into haybale houses, sandbag houses and cobb houses in the walls. really cool.<br><br>ive been drawing ideas for a few lights that use bottles of various materials filled with water that have a small led on the bottom.<br><br>i always mess around with my led flashlights and different beverage bottles to see what kind of light i can get. its kinda fun.<br><br>the cool thing is you can different colors either by using colored bottles, colored or dyed water, or even a colored led. they even have some led's that can cycle through the rainbow.<br><br>my daydreaming about this went so far as to inlcude buying lenghts of clear acrylic pipe and making small wall sconces with them for the van. vertical or horizontal, with water inside and either a set color led or a multicolor led. i had the ends configured in aluminumthat acted also as an attachment.<br><br>ill post a few sketchup pics later.<br><br>all very much like a poormans lavalamp.<br><br>im assuming the bleach is used to keep the water clear. can bleach be dyed with food coloring?