Ok, so remember when I got my first 3 gudgeons and then two days after getting them one sadly died due to what I think is stress? Well its exactly 2 days after getting the new gudgeon and he/she is showing the same symptom the other one was before it got worse BUT its only staying near the top, it is not swimming strange or floating weird... I have the lights dimmed way down to avoid further stress and Im wondering if I should use salt... Any ideas? I really dont need this "replacement" gudgeon to die on me... All the other fish are extremely healthy.