Sick/injured beta fish
I got my betta fish about a week ago from petsmart. (I know, I know-not the most reputable store). Any rate, he has a .5 gallon tank with rocks, a cave, and he HAD a plastic plant. This morning I woke up to find him with what appeared to be his gill stuck in a plant leaf. Immediately, I took him off, took the plant out, but it looked almost like his gill was bleeding. There was no actual blood in the water, it rather looked like something was falling out of his gill. Any rate, I went to class and when I came back he looked even worse.
Upon finding him looking to be what was on his deathbed, I immediately called a local fish specialty store to ask them what to do. They said to clean the water. I put him in a cup with extra conditioner, and he began to liven up. I then took my fish in his cup as well as his tank to the local fish specialty store. They tested the water, said pH, nitrate, and ammonia levels were all okay. I bought him a new, live plant, took it home, and put it in the tank.
Since arriving home and being placed back in his tank, my beta has not eaten, will not leave the surface at one corner of his tank, and is hardly responsive to anything I do. The pet store said I would not need antibiotics unless his gill appeared to not be healing properly.
HELP...what do I do?