It was a combination of removing the bio pellets and running chemiclean within hours of each other. When I found the tank with white cloudy water I knew something was up and just went into save mode and didn't dig any deeper to find if it was ammonia or possibly a bacterial spike that killed everything. I was more concerned with water changes, carbon, and removing anything that was dying so it wouldn't further degrade the water.
That combined with me working WAY too many hours, which were very early or late in the day, it made it very tough to keep up with the tank as all I wanted was sleep.....lol