Do they require a terrestrial or arboreal set-up? Many thanks.
They are terrestrial. Although they do require a bit more height than your average Terrestrial. I keep my adult female in a 12x12x12 with 4" of sub, and a piece of cork to anchor webbing too.
Mine is in an exo terra with deep substrate and a nice exo terra skull, but spends most of her time in her log! She doesn't dig much but made a little hollow under the logOBT are very adaptable with the enclosure they are given. they are prone to burrower so give it substrate to burrower but you can leave vertical space to allow to web up the top part as well.
How do you know when to give water dishes? I have a White Knee and a GBB sling that I put a top to a bottle of water in their enclosure and they seem to do fine. The White knee is probably a bit smaller than a quarter and he/she plays in the water. I'll find her laying in it or will throw dirt in it. The GBB is a bit bigger than a quarter and I dont ever see her near it. Also if the T is getting the food does the size of the enclosure matter? I understand up for aboreal and wide for terrestrial but does the actual size matter?