If you're looking for bottom feeder fish then you might wanna consider some loaches (not the small species nor the ones with the eye spines). I've kept a trio of ACFs with a weather loach for half a decade until the loach grew too big and decided to move unto land (may he rest in peace lol). The slimy coating on the loach and the frog compliments each other when they are close together and prevents any harm from happening especially during feeding time.