The problem starts because I went on a 5-day trip and I let a friend who is an expert in reef take care of my tank, the problem is that when I arrive I see the crazy skimmer, days later one of my acroporas with whitening, I measure parameters and I see everything normal bone kh 7.5 magnesium 1,400, calcium at 420, ph 8.4, nitrates at 4.1, phosphates at 0.05