Hello. I am new here and I am very worried about my axl. He is about 5 months old and has been fine since I bought him until this week. I have him in a 10 gal with a sponge fitler, at about 66- 70 degrees f. Monday I did a total water change because the tank was dirty and the filter needed cleaning. I used decloranated water and rinsed the filter sponge in the same degree water as instructed so not to kill the bacteria. I put him back in and he seemed stressed, but did eat that day. He ate tues,and today also. But he is not acting like himself. He sits in one spot and doesn't move. Usually when he sees me, he starts swimming fast and wil follow me back and forth when i move. Is he just stressed? Should I not have changed all the water? Only do a partial water change ? I did that in the past but the water still seemed dirty afterwards. I don't have any substrate in the tank either. Only 2 plastic plants. If anyone has advice I would really appreciate it. I am so worried. I have become very attached to him. Thank you.