Goldfish acidosis or goldfish alkalosis are possibly occuring if your fish are shooting through the water, trying to jump out of the tank and breathing heavily.
These irregular behaviors occur when the pH of the water falls below 5 or above 8.5. These pH levels actually burn the gills and skin of your fish.
Treatment: Do NOT move fish to another tank, this sudden change in pH will not be tolerated. Immediately do a half tank water change then in several hours do another partial water change. Check the pH and continue water changes every several hours until in normal range.
If water conditions appear normal and fish are still acting irregular check fish for common Goldfish Illnesses.