Hello Everyone!

I have two American green tree frogs in a 12x12x18 inch glass terrarium. I am planning to get the Exo Terra 2.0 UVB (13W) fluorescent light for their cage. Is this the proper lighting for them? I know it doesn't emit much UVB, but I read that they don't need much because they are nocturnal in the wild.

Also, the 2.0 comes in 13W and 26W. What affect would a higher watt have on the frogs? What's the difference? If I do get the 2.0, should I get the 13 or 26W?

Thank you!
Sanimal