My Silver Molly is swimming upside down, I lost one last night and it had the EXACT same symptoms.
Silver Molly that is swimming upside down
The PH is 7.6, Amounium is going from 0-2.0, Nitrite is 0-0.5 and Nitrate is usually 0-.5.
The tank is 55 gallons, and has been setup for about 2 weeks...