MYSTERY SOLVED!!!! I thought I was a HORRIBLE fishkeeper because today one of my clowns went missing. I searched high and low in the tank looking for a skeleton. I tried peering in behind to the intergrated sump. I love the fact there is paint covering the sides but I can't really see in. So I took out a razor and removed all the paint. Low and behold look who I found: Yes, thats my yellow goby, chilling out in the sump. And who else did I find on the other side? Yup, the other clown. Both are eating well. I need to figure out a rescue plan. I'll also have to build an eggcrate guard to prevent them from going back there. Even though there is only about 1" of space it seems to be enough. Sheesh.