Yes in the sump, i have a 6 inches chrysurs, 8inches Queen and french, there is enough space for them, 22" by 30" by 16".
As for adult or juvinile queen or king, it depend on your liking. Personally i like big
fish.
Bro big ben, i did not increase the size, my luck was there if not it will become boxing ring.
Queen adult coloration cut from pic