Hi there, I left my betta fish in the care of my family members when I went out of town for three nights. He was fed daily. Background info: I perform 30-40% water changes weekly, he is in a Blue Planet 70L (18gallon) tank with 8 neon tetras and 3 corydora catfish. Planted tank. No additional aeration. Built in filter. Heater on around 22C. Has driftwood. pH levels typically around 7.0. No added salt. I've had the betta for about 2-3 weeks now, have had the other fish for around 3-6 months. He looked perfectly beautiful when I left and showing signs of distress or illness. I come back home to his fins all looking clumped together and stiff. He keeps gasping and he can barely move due to his fins being scrunched up. His colour has gone very dull which I think is being caused to appear that way due to a faint white film over his scales. I have since moved him out of the tank in case it is contagious and put him my spare 24L (7-8 gallon) tank with filtration and a heater. I have put in some freshwater aquarium salt and stress coat for now. He is still unable to swim well and is gasping a lot/sort of looks like he's yawning very intensely. I have put the heater up to 24C in case maybe the water was too cold or something? Unhealthy Betta by Briana Clifford posted Jul 19, 2017 at 2:47 PM Healthy Betta by Briana Clifford posted Jul 19, 2017 at 2:47 PM Here are pics of him after and before. What is wrong with him and how can I treat him for it? Sorry, typo, meant to say that he was NOT showing signs of distress or illness before leaving.