I am developing a laboratory experiment that involves looking at human blood under a microscope. In particular, I will be looking at how the red blood cells aggregate or clump when a human subject is administered with some substance. In order to try to control for any other factors that might affect the clumping or aggregation of red blood cells, I have been considering not allowing subjects to drink water during the duration of the study, as I thought this might act to declump or deaggregate red blood cells. However, I do not have any scientific data to back up this hypothesis.
My question is therefore: What affect does water have on aggregates (i.e. clumped groups) of red blood cells? Are there any scientific articles/studies showing what water does to red blood cell aggregation? Does it have a noticeable affect, or not?