It's actually older chick, his younger brother is not as bad. anywah I took them to the vet today, they haven't gotten worse but I was still getting a bit worried,over a week is too long I wasn't confident it was going away on its own. The vet did a faecal smear and crop wash, both comes back clean so I'm not really sure what's wrong but I have some antibiotics to give and hopefully that helps? :s Ill let you know what happens!