So I moved two of my three boys into the 10 g that I split 3 ways. I ended up putting two of my snails in the middle divider, and then the two boys on either end. Anyway, tonight when I went to put food in I noticed an iridescent shimmer (almost like oil on water) on the top of the water. I use StressCoat +, and that's the only thing I can think it might be. The fish are acting normal, at least they seem to be. I just changed the water, and I may have overdosed the StressCoat + a bit, but not much. And, I noticed the divider where I poured the water seems to have the most. So, have anyone had that happen? Or should I be concerned about it?