Welcome to our community, like others have said sorry to have you join on such a loss. 11 years is a long time for a a BP and it seems like he had a good home and was rescued by some lucky people.

Definitely don't house Balls together, they aren't social animals. In the wild they find a hole crawl in it and pretty much stay in it by them selves...until mating. Hopefully your female stays strong and healthy. Just make sure that tank was scrubbed down with dawn, warm water, and then bleached and rinsed off again.