Tank size: 25 US Gal.
pH: 7.8
ammonia: 0.5 ppm
nitrite: was 5.0ppm
nitrate: 5.0ppm
tank temp: 77 degrees Farenheit
Fish Symptoms (include full description including lesion, color, location, fish behavior): see description below
Volume and Frequency of water changes: 20% weekly (new tank)...