BP's can thermoregulate in a 10 gallon and anything else they are kept in, its not very hard.
why provide 2 hides and plenty of cover to fill up the big tank when they can just use something smaller and not worry about all the extra stuff to clean and disinfect. also, why put two hides as close together as possible, y not just use the 10 gallon or a tub.
get rid of that big tank or wait and use it for something else. a big tank for a bp is not a good thing.