Your ryukin goldfish are sitting on bottom of aquarium and white film is on scales?

The white film you are seeing is an overproduction of the fish's slime coat due to a crash in pH or infestation of parasites. The bottom sitting is usually consistent with parasites or bacterial infections, but being the skin is milky parasites are definitely suspect. To treat, raise the tank's salt concentration to 0.3% and add an antiparasitic medication to the water.