Ok, switched over to solar glo mvb bulbs by exoterra about a month and a half ago. I have been keeping a log of the uvb output and so far so good. But, 2 of my torts eyes are starting to swell shut and pus a bit. In my opinion its the bulbs as their care is spot on. Im going to take the bulbs back and just run a regular bulb for heat and maybe a sun glo tube uvb but not sure. Sick of spending money on stuff thats hurting my animals. So just a heads up that I think these bulbs are messed up and to BE CAREFUL!!!!