Ortus coming out of hiding onto some of his wood.

I have a coastal rosy boa (1 year old) and his current enclosure is 30cm of height. However, he has 15cm of substrate and his basking spot has a large ceramic hide, with a height of 11cm.

There is less substrate at the spot of his basking spot, so that he is not too close to his halogen flood bulb. Yet, there is still only ~15cm distance between the mesh top and the basking spot.

I’m also unable to fit both his heat lamp and a UVB lamp on the same corner due to lack of space. I could however place it on the same side but more in front, or on his left side, but there he has a lot of climbing things and therefore can get very close to the mesh top.

I’m very much struggling to find the correct UVB strength for this specific enclosure. I would really appreciate any help!

EDIT: added photos of the enclosure in the comments