Making the jump to a 120 g. for my now 10" male Dovii. A little extra space would be nice for him. I keep a small but super colorful GT in a 45 g. I decided He'd be a lot happier in the 90, with a few others, and possibly a female. Probably giving the 45 to my nephew, as he is a fan of Africans. I realize the 120 still may be cramped down the road. There are approximately 10 fish stores in a 20 mile radius near me, so swapping or finding new or used tanks isn't that difficult. Had a quick question on substrate? Is sand ok, for Larger cichlids? I know they (Dovii) dig a lot, or should I stick with plain gravel for the 120?