Cory,
First, if you're trying to run a ULNS, you would be better off running Alk. near NSW levels. I shoot for 8.0 and everything seems happy there. Second, boost your Ca up to 420 or so. Third, poor color on montis is almost always a sign of low potassium. There used to be test kits made by Merck for this but I don't know if they're still available. Dosing trace elements can help to restore those levels as well but that's a mixed bag. One thing not mentioned is flow; too low and your corals won't be happy and that stress could cause what you're describing. Change one thing at a time, give it a week, evaluate, and repeat until you've found the problem.