Good morning. I hope someone can help as I am in dire straits. I have 2 4-year old goldfish in a 55G tank, a fancy and a comet. The comet has always been the more active and speedy one. However I noticed the other morning he stopped taking food. He is also acting very slow and lethargic. Not sitting on the bottom or gasping at the top but just slowly drifting around the tank. Their normal diet consists of goldfish crisps daily, a few baby shrimp as a treat and blanched spinach once a week. My wife, who works in science, tested all the levels. Everything is normal and within range, I'm sorry but I don't have the numbers. I do a 40 percent water change every week and always replace the foam filters. I noticed on Saturday the comet, who is more voracious, wouldn't take the spinach. I have been all over the internet trying to figure out what might be wrong. I tried Melafix for a couple of days as a precaution but also read that can affect appetite. He's a bigger fish so I'm not sure if he could be bloated but I read about constipation. We gave him an Epson bath in a bucket the past two nights and after the first one there was a definitely bigger poop with a lot of substance in it. Last night is was just stringy. We never give them live food and have no plants in the aquarium so I am thinking it isn't parasites. I tried shrimp again yesterday just to see and he actually took two pieces in his mouth but spit both out. The fancy has no issues, swims and eats fine. I don't have a hospital tank to put him in which is why I am trying to the Epson baths. Any help would be appreciated as I am very, very worried. Thank you in advance.