UVB Placement

[shawnalansmith77]

So I am in a FB group and posted this pic. I was told that my UVB light was too close. It's 13" from the basking spot to the top of the cage. The light is attached to the back, so I'd say it's probably 14-15". It's a ReptiSun T5 HO 10.0 and was told that it needs to be 20" away if it's in the cage. Everything I find on here and other sites say 12-18". Can someone shed some light on this for me? No pun intended. Also, are the UVB test cards worth it and is there a reasonably priced electronic gauge that's good.

 

[KarrieRee]

For best effects the UVB should be directly over the basking decor piece w/ a reflector on the hood / fixture- distance for a T5 is 12-15 inches -- for a T 8 is 6-8 inches w/ the same recommendations as the T 5-- reflectors direct the rays downward toward the dragon giving more power to the rays which is beneficial to them --- 20 inches is to far for a T 5 --