I have three frag tanks plumbed into 180 gallon main display. Roughly 350 gallons. I did a 25% water change using instant ocean and my magnesium drop from 1300 to 1250. This is nothing new but this is the first time I’ve been able to do a larger water change, but with this batch, the most I’ve seen the magnesium drop. Last night I added 32 mL of magnesium and it brought it up to 1260. When I came in this morning and looked at the tank, it was white, cloudy, and all my acro are RTN . No temperature change, phosphates are .06 nitrates are 5.2ppm. I put an ammonia badge in the tank and it did not change color so I’m not sure if free-floating ammonia is the culprit? I did detect a very foul smell in my shop where the tanks are located. Alkalinity has not changed. Calcium has not changed pH has not changed. Not sure where the white cloudy came from but preparing for a massive water change currently started running carbon. Any ideas?