Wow...I've had a 4" pink jewel for a couple months in a 20 gallon that is cycled with low nitrates. I returned home one night and noticed the tank looked different. I couldn't find the jewel at all. There's also an ice blue zebra cichlid and a jack dampsey, both smaller. First I thought they ganged up on him, but then looked around and sure enough there he was behind the stand! He was a jumper but I never pictured him making it out of the 2" gap from the cutout to fit the filter in the back. Well, at least the other fish are happy that they get to pig out a little more without the big guy taking the food!