Hey! So my husband and I recently bought a 55 gallon tank from a friend. It has 2 lemon oscars, 2 pleco, and 2 Cory catfish. All that was in the tank was a couple rocks and the fish when we got it. Today we got some black rocks, 5 or 6 different decorations and redid the tank. The fish seemed a little stressed when we were moving things around, but when we were done they came out of hiding and were swimming around and acting happy again. Then we noticed one of the oscars had turned a gray/green color. Is this normal? just from stress? Only one of them turned. The other is the same color. Will he turn back to normal? His name is lemon so I sure hope so. Hah