In tank 15 there were two spadefish, they were small and each had either a unique mark or no mark. We had also named them Cookies and Creme. Cookies has a mark on its side that looked like a burn mark. Creme had no mark which earned them their matching names. They used to eat small pieces of squid. For this tank I would add more water when it was needed. Sadly, both fish died over a weekend.