First question, is UVB necessary? I only have ecuadorian and Caribbean crabs right now but I plan on getting some violas at some point.
If UVB is necessary how would you guys recommend putting the light in? I don't have a lid for this tank so I was planning on just doing 2 DIY glass lids but I've read the glass will filter out the uvb so do I need to get like an aquarium hood with the light fixture in it? Could I just do one side with the hood and one side with the glass? I know humidity is already an issue with a larger tank so I was wanting to just do 2 glass lids and mounting a light above the tank (for viewing purposes)
Speaking of humidity do you guys think I should put bubblers in the pools I'll put in there? Do I put the bubblers in the salt water pool also?
Also any information on false bottoms would be great. I am not sure if I'll make one yet because I just wanna get this set up done lol
I'll probably have lots more questions but the lid and light is most pressing right now

Thanks for reading and any advice is appreciated!!