Im new to the site and I have a 20 gallon brackish tank with an Archer fish and a Spotted puffer, i currently feed them a frozen seafood mix. Is this best or should i be feeding them something else to help them "thrive." Also i was thinking of getting another spotted puffer, and something to help keep the tank clean. I know i will still have to clean the tank by hand, i just want something to help with the small stuff/un eaten food, what should i get?