I have a tire track thats about 17" x 2" dia he has stopped eating for about 3weeks Ive tested and tested my water......changed the water...etc he used to only eat krill and live ghost shrimp.. but he wont touch that any more....wtf????...my friend says his does it some times but never for more than a week. any suggestion would be great...ohhh btw he still looks healthy no heavy breathing skin looks fine doesnt look like hes dropped too much weight.