i was worken on my 150 doing a water change. i have my 48" light that sits right on glass, ya the glass gets hot but i figured its fine. but lucky for me i was down there, the glass just shattered into about a dozen pices and the bigger heavy pie that was razor sharp almost hit my ray, def would have killed him, missed him by an inch no lie, that and i caught the light b4 it went in. is it ok that i have my light right on glass,, i thoght it would have been fine. i hope ace hadwear has g;ass they can cut for me, anyone know of a good place to get a cheap pice of glass cut bc right now i have a bin over the top and i cant turn on light bc it will melt it. thanks for any advice, anyone know how this could have happened or wher to get a new pices of glass