Ok. Huma huma said for a detailed explanation, here it is. I got home from work two days a go when i went to do my daily tank check and feeding, he was at his usual spot next to the overflow box. When he got off to eat, he was a dark blackish color, when he is normally white. This happened before, but it only lasted for a couple of minutes. He was literally crashing into the tank walls, so i got him in a transportation box and put him in quarantine. His color started to return, but he was still crashing. I keep checking up on him, until 2:00 am when i go to let out my dog, i find him dead in the quarantine.
Parameters are normal, and nothing dropped or anything. Salinity was 1.023, ammonia was 0, nitrite was 0, nitrate was 15, ph was 8.1. If you have any ideas on what problem this situation? Thanks for your support!