Does a protein skimmer use up more water?

[Blom]

I would imagine that there would be some evaporation through the use of a skimmer. The pump that is being used for flow through the skimmer will add heat and thus evap as well. As for the the water properties changing I have no idea, Im sure someone else on here will be able to chime in. If the skimmer was bought used than maybe there was some additions through that. But what do I know... Im a blonde