Thanks for the reply. I have a solar meter and understand the uvi levels I should be providing but I was more just curious as to how much space I should have between the fixture and the ceiling of the enclosure. I thought I read somewhere on the forums here that in the closed chamber you shouldn’t attach the fixture to the top to avoid condensation buildup at the top of the fixture.To choose the correct height, the question is what is the UV index (UVI) at tortoise level. The only way to tell for sure what the UVI experienced by the tortoise using your specific lamp is to measure it with a Solarmeter 6.5. The manufacturer most likely provides a rough guide of height vs. UVI for the specific bulb and fixture that you bought. Without a Solarmeter, this is all you can use to set the correct height of the UV light.
For your Hermanns, shoot for a UVI of about 3.0 at tortoise level, and run it for a couple of hours midday.
That’s how mine is now. Just a very small gap in between. It just stood to reason a bit more space would be better. That’s why I mentioned I had some 6% and 12% bulbs. The 12% is in now but is attached as mentioned above. I am going to switch to the 6% and drop it until it is where I want my uvi to be. Should give me a few inches to work with anyway. I’ve bought extras of tons of the major stuff I’ve bought. While I hope all four of the hatchlings will get along for some time in the event there were issues in easily getting something more than serviceable ready in the event things don’t go smoothly at any point. I’m going to put my substrate in soon and see how it is once I switch bulbs and have the exact level of the substrate. I’ve only about measured guessing at around 4 inches of substrate.I used it almost attached to the ceiling and it broke down 6 months later. What i use now is plenty of space and has been working well for 7 months. I couldn't think condensation would be a problem at the time