Hello I started a salt water tank about 6 months ago and have taken it slow. I have a 46 gallon bow tank and used crushed coral for the bottom and currently have about 30 pounds of Tonga live rock. I am using an Emperor 400 bio wheel filter system, stealth shatterproof heater, and a Satalite duel bulb lighting system that runs blue and white light as well as a moon light at night. I have been running the light for 9 hours a day and seems to make a big difference from the other light that I used. I have 7 fish in the tank at the moment they are 2 clowns, 2 yellow tail damsels, 2 domino damsels, and another blue damsel. I thought I was all set my lvls looked great although the calcium seemed a little high running over 500 not sure if that is good or not. Thinking everything was great I added a peice of green tree soft coral and within a day it started to look bad and within 4 it was dead. After this happened I retested my tank lvls and Nitrate 3 was running well above 100. Please could someone look at the things I listed in my tank and give a little advice on what I should do from here and maybe some insite to as why the coral would have died so quickly or even at all thank you.