Well it turns out my city has cranked up the chlorine in the water due to an insane amount of rain we've had and I've been dumping chlorine that made it through my ro sytem into my tank. After doing a 30 gallon change and killing more coral I was making more water when I got a whiff of what I can only describe as the smell of a city swimming pool. Upsetting but at least I've pin pointed the issue and can stop killing my own coral with water changes now....grrrrrr
I think this was my issue when I lost thousands in acros two years ago. That and my ASO valve wasn't turning my RODI unit off so I suppose I was depleting my filters quicker than I thought and pumping bad top off water into the container. Bad news for me.