Hello! Yesterday I noticed my dwarf gourami not eating at all. Today he still didn't have much of an appetite and just hid behind the themometer when food came. Just now I come home and find him lying at the bottom breathing rapidly and very weak. So weak the filter picked him up and I had to unplug it. I did a 25% water change just now, even though I had just done a 40% in the morning. All the other fish are fine and swimming around like they always do, all eating and stuff. They are in a 20g I have had set up for about 3 months now, and I have 2 20g filters running in it. I have an airstone running and the water level is set low so the filters give air too. I don't know whats wrong with him, and am afraid he is going to die. Any help would be appreciated! 
Any reason why he died would be appreciated though!
