I need help with my FBT.. I have 4 in a 20 gal tank. One hasnt been eatting and get very skinny, slow, and not active so i seperated it from the rest (thinking he was slower than the others because he hasnt been eatting) he ate a few crickets. His eyes are cloudy and looks like there is something on each eye and i cant see the actual eye. He also went from lime green to a dark hunter green. Idk what to do, hes not getting better. The other 3 are perfectly fine.