I set up some bubble lights this year that I bought 3 or 4 years ago. They worked great for the fist day or two then about 80% of them just stopped bubbling. I thought they might be some rip off cheap imitations that only work for a couple hours. Turns out they just needed a little reinvigorating. I do have one that has something stuck on the inside of the glass that I can not shake loose and that one just refuses to bubble for some reason.