So just within the last few days, I’ve noticed 2 of my corals receding or dying off and i have no idea why. 1st is a frogspawn that I’ve had for over a year, and the 2nd is a hammer I’ve had for 3 weeks. Tank is a Waterbox 130 that I’ve had running for almost a year and a half, has 14 fish and mostly lps (hammers, torch and frogspawn) with a few softies and running 2 XR-15 Blues at AB+ lighting schedule for 10 hrs a day with the following params - temp 78, salinity 1.026, alk 9, calc 470, nitrate 15 (have gotten it down from over 40 in the last 2 months) and ph 8.1 - 8.3. The corals in question have not touched other coral nearby, and doubt any fish i have are bothering them either. All other coral in the tank seems to be thriving. Anyone know what could be going or what i could do to help this from happening to others?? Thanks!