you said that your water is milky. does it have a greenish tint to it?
here is a link to some algae types. looks like hair algae to me but i'm not the best at identifying different types.
also you shouldnt have 0 nitrates. you need to have a balance of nutrients in your tank. you should have nitrate, phosphate and potasium (which are your macros), and also iron (one of your micro's). not having one of them can cause algae growth