Exodus 7:20-21

And Moses and Aaron did as the Lord had said; and when his rod had been lifted up and stretched out over the waters of the Nile before the eyes of Pharaoh and his servants, all the water in the Nile was turned to blood; And the fish in the Nile came to destruction, and a bad smell went up from the river, and the Egyptians were not able to make use of the water of the Nile for drinking; and there was blood through all the land of Egypt.