The absolute easiest way to clear it up is to use pro-clear as directed on the package. Use it for a full week, no matter how clear it is. If you have algi eating fish, make sure you feed them plenty. I haven't used the stuff in over a year. You can also rent or buy a diatom filter.
Now, if you have the time, I would definately do the scrub routine, as all our tanks can use that from time to time.
This stuff has always worked for me and killed no fish. This is only by experience. Perhaps there are other perameters I'm not aware of. (water levels and such)