In the 10 Plagues of Egypt, the water turning to blood is considered one plague. but did you ever notice it has 2 parts?
PART 1- The main body of water turns to blood (the Nile) like the "seas" during the 7 last plagues turn to blood. (Plague 2).
Get thee unto Pharaoh in the morning; lo, he goeth out unto the water; and thou shalt stand by the river's brink against he come; and the rod which was turned to a serpent shalt thou take in thine hand.....Thus saith the LORD, In this thou shalt know that I am the LORD: behold, I will smite with the rod that is in mine hand upon the waters which are in the river, and they shall be turned to blood. And the fish that is in the river shall die, and the river shall stink;
Exodus 7:15,17,18
PART 2- This phase affected the regular drinking water throughout the land, like the the rivers & fountains of water turn to blood during the 7 last plagues, for He gives them blood to drink for shedding the blood of the saints. (Plague 3).
And the LORD spake unto Moses, Say unto Aaron, Take thy rod, and stretch out thine hand upon the waters of Egypt, upon their streams, upon their rivers, and upon their ponds, and upon all their pools of water, that they may become blood; and that there may be blood throughout all the land of Egypt, both in vessels of wood, and in vessels of stone.
Exodus 7:19
Always DIG DEEPER