Yeah the smallest tank recommendation for any dwarf cichlids is 20g....if it's breeding pair I'd put em in a 30g at least.
A 10g you could have another tropical...or a betta.
You could maybe try your luck with Neolamprologus multifasciatus. they are a small cichlid that live in shells, the males get 2" max and females around 1". I havn't had any personal experiance with them, but a lot of people seem to like them! plus they look absolutely adorable