What would happen if SCP-009 had physical contact with water?

I think that SCP-009 would spread, the water would be frozen.

IIRC SCP-009 takes up all available space right? So since water molecules dont always directly touch wouldnt it take up the space between the water molecules right?

Since water is a liquid, it's molecules are spread out, the ice will go in-between the water molecules. If the the ice is cold enough, it might even freeze the water, (Depending on the temperature of the water.) and the water might melt the ice, if possible. I've never looked into the physical properties of this SCP, but I kind of doubt it can melt, so that third possibility is off the table.