Hi - "ALL my parameters are 0 PPM" may not be desirable - which parameters? Retest and post your exact results for alk, calc, nitrates, phosphates, etc. You may want to slowly up your
SG a bit to around 1.024 - 1.025 and ph to around 8.2 - 8.4 range. How long have you been adding the foods you mention? Were they ok before the foods? Is your skimmer pulling out lots of stuff daily? It should be with a tank that size and with the bioload (
live rock, fish) you list. Also, emperor angels get really big!