Quote Originally Posted by maskedburito View Post
I have heard this a lot. My beardie has a ho t5 tube. But for the breeding gecko terrarium I want to use a coil bulb I have. I have some friends who suggest trying it for cresties.

But I heard the old coil bulbs are bad but the new ones are much better. If it's kept at a distance and not angled at them so it's not directed into their eyes is ok. Hoping that's true...
Problem is UVB tubes/bulbs need to be at a certain distance to be effective. 6" for T8s and about 14" for T5s. This is unfiltered through a screen which can cut out up to 50% of the UVBs effectiveness. Now I don't know the effective range of a UVB coil but if you put it at a distance and it has a screen between it and the animal, then how effective will it be? Also not directing it into their eyes is a moot point as UVB will radiate no matter what. I mean even in shade there will still be UVB. Get a solarmeter and you can check it out.

Now maybe the new ones are redesigned and not putting out the lower end of the UVB spectrum. I have no idea as like I said I have used T8 and T5 tubes forever and they have worked for me and are tried and true so I have had no need for UVB coils. I guess you'll find out though, just watch the geckos for any signs. Best of luck.