Elliott started gasping and laying at the bottom of his tank after his water change. After careful inspection, I noticed that his water is two or three degrees higher than normal. I added a bag of ice, and it has dropped to normal. I also added a little extra dechlorinator, in case chlorine is the problem. I have increased his water changes to twice a week because I took his filter out. He lives in a five gallon tank. I use the same bucket to clean his tank as I do my goldfish. Normally, I clean Elliott's tank first, but I did the goldfish first today. Could he be sick from trace amounts of goldfish water?