This past week I picked up some nice size pruple digitata frags for FREE from a fellow reefer. The frags are about 3 to 4 inches in size and branching like crazy with some color to them. He said he was not able to take care of his tank for a couple weeks and if my water quality is ideal they will color right up. Well, I placed them at the same height as my birdsnest (very healthy) and my monti cap (growing like a weed). Everthing was going well until I noticed last night that one of them is losing its color on the bottom but still has its polyps there. Then tonight I noticed the same thing from the other frag a small lighter color area almost like a blotch. The strange thing is I purchased two small 1 inch digi frags 2 weeks ago, they are placed lower in the tank and seem healthy. My nitrates and phosphates are non existent. My alk is 9 but my calcium is 350 (just started dosing tonight with calcium). Should I be worried at all or are the corals in some what of shock going from 4 500w mh to a Tek 4 bulb T5 system?