Hello, we have a goldfish approximately twelve years old, who I noticed is losing some scales on her sides.. I posted about a month ago about one of her tank mates who died, he was also approximately 12 years old and we've had both since they were small. We don't know why the other goldfish died, but testing the water the ammonia level is zero and the water quality otherwise seems to be ok. The general consensus on here when the other goldfish died was that maybe he just died of old age. Two days ago, our Dojo loach died, who was another tank mate. I'm pretty sure he DID die of old age, as he exceeded the average life span for those..he was over 11 years old. This leaves our goldfish by herself except for a sucker mouth catfish who is no company at all. She (the goldfish) seems to be ok, but I have seen her lying on the tank bottom a couple of times in the past few weeks,and there is the scale loss thing, which is noticeable, although she's lost a few scales in years past and it never seemed to get any worse. She eats well and today I gave her a couple of frozen peas, which she likes, and she polished those off. I've read that losing scales may be caused by stress, and I'm assuming she could be stressed by the loss of her tank mates, especially since she is partially blind and was using the other goldfish as a guide a lot of times, and she's been with the other two fish her whole life...the past 11 or 12 years. Now she has no companions at all. I don't know if that is her only problem....possibly not...but I'm wondering if we should try to introduce some new (small) goldfish in the tank, as possible new companions for her. That might be a stressor too, but I'm not sure which is worse...just curious what others think.