They all tested at the bottom/zero or the next spot up. Tank is fairly new still (thought I don't think that caused this major die of - after not having lost any fish) I have live rock and used bacteria starter to cycle.
We had 1 valentini puffer, 1 tomato clown, 1 very small blue tang.
We still have - scotter blennie (not real active today but still alive) 1 purple lobster - never active!! assorted snails and crabs.
I'd like to think that the puffer might have done this as the tomato was just added yesterday - maybe they were duking it out after we left for home. - If that's the case - they both lost.
I also did the rubber band thing at home last night and all is fine in there. I live far from work so I couldn't rush home after the deaths and work and take it out so it stayed all night and today without anything happening.
btw do all puffers expell toxins when they puff?