I was gifted a 70 or 75 gallon (don't recall exactly) saltwater aquarium with live rock and 2 clownfish. My husband and I have since added 1 Yellow Tang, 1 Coral Beauty, and 1 live rock. After comparing the new live rock against what I was gifted it appears as if the others are dead. Is there anyway to "bring them back" so to speak? What can I do to ensure that my babies flourish? I would also like to add coral at a later time and I don't know if that will have an effect on what is done now.