So basically I got a fish tank in December, it’s a 60L tank, I knew what fish I wanted in it so after adding water to it and leaving it to cycle for over a month I went to Maidenhead aquatics to get my fish, I ended up buying a heater and got decorations for my tank and went home and set it up, I also got some drift wood and let it soak for 5 days then put it in the tank. After 5 days I went back and got some Rosy Tetra and Diamond Tetra, 3 of each, as they were a larger breed of tetra and grow to 4/5cm and I knew I wanted angel fish. I then waited about 2 weeks, the Tetra settled well and I went to buy my angel fish, I got 4 angel fish, I introduced them properly and added stress coat before I added them to reduce stress. And yes I am aware that my angels will grow to 18cm so I wil eventually have to move them but the place said for now they will be fine. I fed them the day after I added them and noticed one of my angels wouldn’t eat and kept sitting in the same spot, the other angels were fine and were swimming together and eating but this one wasn’t acting the same. I turned the light off to see if he’d move because I thought he could be stressed, the next day I turned it on and he’d moved but wasn’t very lively, he was in the open area rather than hiding in the plants. I then thought I could feed him but when I added the food it seemed as the tetra scared him off because when they started going for the food he went and hid again. I looked at him again today and noticed one of his fins looks like it’s been nipped and he’s hesitant to move it and moves really slow but he’s not just sat in one spot anymore and does seem to be acting better than the first few days as he’s trying to keep up with the other angels. I don’t know what to do but I want to help him and really don’t want him to die from not eating or stress.