So a little background, I rescued a goldfish from a hoarder house, and after a battle with various illnesses and adapting to a clean environment she pulled through. She has been in a 10 gal since I wasn't sure she would survive, and since she has I got a 40 gal breeder. I ran the new filter alongside the old one in the 10 gal for about 2 weeks with a bio stone directly underneath it. I put about 2 cups worth of substrate, the filter, the bio stone, 4 artificial plants, and 1 hideout from the old aquarium into the new one. Everything else is new. I let the new aquarium run for a couple days to get the temperature to match her old one (our "cold" water comes out in the mid 80's here). I tested both aquariums and ammonia, nitrate, nitrite, and water hardness matched perfectly. PH had less than a .5 difference. I decided to move her into the new aquarium. It's been almost a week and she just sits at the back of the aquarium by the filter intake behind a log. She hasn't had any interest in food. Instead of happily swimming over when she sees someone she hides. I put my hand in the tank a few days ago to fix a runaway java fern and instead of swimming up to and brushing up against my hand like she used to she swam as far away as possible. I've also noticed some scales have gone missing but I don't know if it's from her swimming between the filter intake and the glass or something else. She developed stress veins in her tail fin the second week of having two pumps running in the 10 gal but it seems to have finally started to fade today. I have been testing the water in the morning and again at night every day and ammonia, nitrate, and nitrite have all stayed at 0 and ph hasn't changed. The water is getting a little cloudy but I assume that's from the uneaten food. Is it just a shock being in a bigger/different environment? Or did I do something wrong? Is it possible she's sick again? If it's just moving stress how long before she goes back to her happy self? Also, how much water should I do with the weekly water changes? I always did 50% with the 10 gal and vaccumed the gravel every time. Is that nessicary with a 40 gal? Sorry for the long post.