I took down my big tank and put my remaining fish into a smaller 40g hex tank. Since the move my pleco has been going to the surface and grabbing air alot. Is this a reaction to a low level of dissolved oxygen in the water or a symptom of something else? The tank is a bit overstocked right now as I am still trying to get rid of a few of the fish. If its the crowding then I will not worry as it will soon be resolved but I want a little lead time if this might be a symptom of something else. He is eating fine and looks healthy, just has this new behavior. Oh, hes about 10" long and a common pleco I think. To be honest I dont know much as far as the different varieties of plecos
