A week ago, I added several softie, mushroom, and Zoa frags to my tank. The finger leather looked great, but started drooping earlier this week. I gently acclimated the leather to a place midway in the tank. Today, after coming back from a two-day trip, one of the arms appears to have completely rotted. All of my levels are stable and nitrates are at 0, although there was a two-day span (Sunday and Monday) where the salinity was at 1.019 - but everyone else is doing fine. The finger leather was also about three inches away from a large lavender mushroom during my trip. I found a few small black line-like things on it, but they do not appear to be moving. \n\nAny ideas of what might be happening?