Hi all!
I have a nine year old, female, blackmoor goldfish. In the last year she has had several episodes of struggling not to float to top of the tank. I've solved these issues with fasting and diet. Two weeks ago she sank to the bottom of the tank and is stuck there in an upright position. Initially I put her through the same fast and diet change that worked in the past. She is not constipated and is still eating well but cannot leave the bottom of the tank. My tanks numbers are optimum, I do 70% water changes weekly, my filter is cleaned every 30 days and she is the only fish in the tank. The only water additive I did was aquarium salt when she went to the bottom. I've removed 50% of the water in the 40 gallon tank so she can, (with effort) get to the suface. I've also removed all elements from the tank so she has room to skim along the bottom and gather up food. I'm thinking that this is a permanent situation as I've read that this often happens in "fancy goldfish", but would greatly appreciate suggestions for getting her swimming again.