I have a 120 gallon tank with 2 175w 6500k metal halides and 2 actinics, trickle filter, protein skimmer, 1200 gph pump, 150 lbs of live rock, 4 fish, 5 corals. It has been set up for a month and has been running extremely well. My readings are; ammonia 0 Nitrites 0 Nitrates 0 PH 8.4 Calcium 440 Iodine 0.03 temp 79 salinity 1.021 I regularily dose with stronium and magnesium. I purchased a sun coral and finger coral last week from Big Als aquarium, The finger coral had been in the store for some time. The sun coral had arrived the day before. Now after a week, these 2 corals are dying.... Any ideas of suggestions I can try to keep these alive?