for a few weeks occasionally after a night or two the water goes yellow in my hamsters water bottle. it doesnt happen straight out of the tap and sometimes it doesnt even happen but how do stop it and what is it? my school has hamsters you can take home and we have the pregnant one for the weekend and its happened to her even though i havnt changed the water. out of my own five hamsters it has happened to the two grown male syrians but not the other male.