4 And the third poured out the bowl of himself into the rivers and into the fountains of the waters; and it became blood.
Revelation 16:4 Cross References - Diaglott
Revelation 8:10-11
10 And the third messenger sounded, and fell from the heaven a star great burning like a lamp, and it fell on the third of the rivers, and on the fountains of the waters.
11 And the name of the star is called the Wormwood; and became the third of the waters into wormwood; and many of the men died of the waters, because they were made bitter.
Revelation 14:7
7 saying with a voice great: Fear you the God and give you to him glory, because is come the hour of the judgment of him; and worship you the one having made the heaven and the earth and the sea and fountains of water.
Revelation 16:5
5 And I heard the messenger of the waters saying: Righteous art thou, the one existing and who was, the bountiful one, because these things thou hast judged;