Ok, looks can be decieving at times, one of my sand tanks looked nice and clear, but when i looked at it from the side it looked cloudy.
Why is that? because of differnt depth. most aquiariums have more depth from a side view than from a front view, and small levels of cloudlyness are more visible that way.
Anyways, I just do water changes to rid of cloudy water and it helps. There are checmicals for water cloudy, some of the descriptions include " includes a polymer that makes all the cloudy material lump up and fall to the bottom for easy removal" but even then it suggest doing a water change.
until someone with more knowledge comes along with a more consise diagnosis, I woould suggest water change. Just because you have all the great equipment does not make you immune to tank crashes and water chemistry change, sometimes it just happens and small water changes over a period of time have helped me.
Goodluck with your cloud problem.