first of all, all your tank parameters are to high. heres a list of the ranges that they should fall into.
nitrates should be as low as possible
alkalinity should be between 9 and 12dkh
calcium should be between 400 and 450
phosphates should be around .03 to .1 too much phos. in the water is a problem and too little also allows the nitrates to spike
temp should be between 76 and 79 anything over 80 corals start to close up and turn brown.
ammonia levels you want at zero with that elegance.
coral beauties are beautiful fish but they are known to nip at sps and lps. this fish might also be an issue.
what type of lighting to do you have? this can also play a big roll.
also just a small note, the elegance is happiest when the skeleton is burried the the gravel up to the tissue layer.
hope everything turns for the better after a couple large water changes.
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