I had bought a 160 watt zoo-med power sun (mvb) and was using it for around 3 months maybe when i started to notice a strange twitch from my tegu. This was odd to me due to the fact my tegu was growing very fast, had/has a huge appitite, and very active and alert. I tested the bulb and the uvb output was next to nothing. So maybe a returned bulb that was boxed and resold or a bad factory bulb. One things for sure, from now on i will always test a new bulb the day of purchuse.... How long will it take me to get uvb back into my tegu and stop these strange twitchs?....And should i go heavy on the zoo-med calcium/WITHOUT-D3 on its food?... I have read on here that i should feed an extra mouse a week until tegu improves?..I have never had a reptile of any kind with this strange uvb lacking twitch...HELP ME OUT GUYS/GALS!!