UVB lighting


I just got a Reptisun T5 HO 5.0 uvb light bar for my cage. I keep reading all different things about how far down I should move a few branches for her to be safe. The uvb light will be sitting right on top of her cage.
Thought someone on here might have some answers for how far away she should be from the light. Thank you.
Zoomed has there own reference chart you can start from but it only a starting point IMHO. Many things can change the your UVI. To add to the chart the distance should be measured from the your chams dorsal. https://zoomed.com/wp-content/uploads/Choosing-Correct-UVB-Lamp-2018-07.pdf

Klyde O'Scope

Chameleon Enthusiast

Be aware that brand-new UVB bulbs have a burn-in period of 50-100 hours wherein they can put out significantly higher levels than they are rated. When I first installed mine, I was getting UVI of 3 at 12" below the screen, which meant my perch needed to be lowered to 14" below screen to account for height of the cham.

After a week or so, I was able to raise the perch up to where he gets 3.0 on his back.

To be sure—and save money in the long run—a UVI meter is suggested/recommended, either a Solarmeter 6.5x or DIY version. All T5 UVB bulbs are rated & warrantied for 1 year. I happen to have one that's over 2 years old and still going strong. Without the meter, I'd have replaced the bulb twice by now, so it's saved me the cost of 2 UVB bulbs (so far). The more enclosures (bulbs) one has, the faster/sooner the payback & savings.

The bulb in my chameleon enclosure is 15 months old and still at full strength as per meter.
One way to extend bulb life is to run it only 10 hrs. per day instead of 12. Very little UVB can penetrate the thicker atmosphere at dawn & dusk, so I've timed them to turn on 1 hr. after "lights-on" and turn off 1 hr. before "lights-out".
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