Goldfish staying on the bottom of the tank
My 5 year old goldfish has been sitting on the bottom of the tank.(the fish closest to the glass) My children won 3 carnival goldfish last week and added them to the tank, I took them out today. I did a 50 percent water change yesterday and a 1/4th water change today. No change, so I went to a local fish store and he suggested remove the new fish and add aquarium salt and melafix to the tank. My tank is 55 gal, and I was nervous about the total dosage so I lessened the amount to 5 ml for every 10 gal, I did 5. The salt is where I only added 4 tablespoons instead of 1 tablespoon for every gallon, it seemed excessive. Also our water is hard water that is softened. So far the fish is still in the same spot and moves occasionally. I did try peas but he didn't seem interested. Is there anything else that I can do to help my little friend?