God told Moses to tell Aaron to bring a plague on the waters of Egypt, turning all the water into blood. God said blood would be everywhere in Egypt. All the natural bodies of water would be full of blood, and any containers people had been keeping water in would also be full of blood. The Bible says Moses and Aaron did just what God had said, and all the water was changed into blood, and blood was everywhere in Egypt.

After that happened, it says the Nile smelled so bad that the Egyptians couldn’t drink its water. What water? Why would it say that if there wasn’t any water anymore? It sounds like the river was just full of stinky water, not blood.

Then it says the Egyptian magicians were also able to turn water into blood. How could they possibly do that if all the water had turned into blood already? There must have still been some actual water for them to use, that hadn’t turned into blood yet.

And indeed, it says people were still able to get real water in Egypt. All they had to do was dig near the Nile, and they would find drinkable water. So no, not all the water in Egypt was turned into blood.