Yesterday afternoon, around 4PM, I noticed my Calico Veiltail had popped up to the surface like a cork! I found no info as to what to do for him so I called my aquarium store. Was told to add half the dosage of Melafix. I removed my regular filter with charcoal and replaced it with the one that I keep for medications (charcoal removed). Around 10PM, Mango was swimming much better. At 11PM he was on the gravel sleeping as usual--back to normal. This morning I was apprehensive, but no worries! No food today for either. They can eat the Wisteria, etc. until tomorrow. Was told to put my regular filter back in and do my normal water change this week. I am a novice of 2 months and started with a 10 gallon. Just purchased a 20 gallon long, have set it up and today added 2 comets about 2" long each. Next week I shall add 2 more in order to cycle my new aquarium. This is definitely a learning experience. Love fancy goldfish!!!

FYI, Mango had this problem 3 times!!! Now, I only feed frozen brine shrimp, bloodworms, etc. No problem since no longer feed flakes.