Herein lies the problem. We are all calling these zoos. At least the ones I got 3 years ago not sure if they are the same trouble makers were palys from what I know a paly to be. Long stems, bigger heads (maybe just smaller than a dime).

So I would say yes they were probably palys and I incorrectly said zoos.

I dont think they had heavy metals in the system since they came out of an established tank with inverts. I also had the exact same symptoms with all the bristle worms coming out of the rock and dying on the sand bed along with everything else. There was also a bad smell in the water which smelled exactly like the palys before and after I put htem in the tank. I also made sure to put just the rock and corals into my tank and not the water it was transported in.

I guess its truly hard to ever tell what did it but being so close in symptoms its a crazy coincidence that within 7 hrs of the palys being in my tank everything dying.

It's hard to tell, it could be the palythoas, but this could also be caused by bad bacterias in the water. Anything in the vibrios family. they are very dangerous and cause all sort of disease in coral and humans. Brown jelly is caused by this bacteria and protozoa taking over.

If it was smelling bad, I would say a bacteria because palythoas are gewy and slimy but they don't smell much, but bacterias are extremely smelly.
Just take a breath at the skimmate and you will see :)

There are definitly a lot more dangerous stuff in the aquarium than just palythoas slime.

It's just hard to visualize everything dying in a tank only due to some palythoas. I have so many in my tank and I frag them and they slime like crazy and never caused any harm to anything. I have a few different types of wild button polyp palythoas that fit the description of the dangerous specie, yet nothing has hapened. I have one that is starting to become quite pretty with a peach center and becoming really huge. It was just brown at the beginning.

Last night the sump got a little low and gurgled a bit topped it up after that throat felt a little scratchy dog started pacing opened all the windows to air out the place.....wicked stuff and I have to say we don't live in a tiny apartment we have a 2100 sqft house and the tank is in the basement.

Had enough took the day off today and ripped everything down found the dead fish 1st I thought it was a sponge on the bottom of a rock. I had around 100# of LR and about a 4" sand bed. The sand.... was..... nasty it reeked of H2S and was jet black about an inch down. Blocked off the basement had high powered fans in the basement windows and wore a full face mask. Went outside once to cool down after I removed the sand and walking around the back yard all you could smell was rotten eggs. House smells nice a clean now and the wife is happen once again.

Sand is on the way to the landfill rock is outside in tubs getting a fresh water bath. Tank was hauled outside washed, vinegared scraped down with a razor blade back painted black. Stand cleaned up and tank back in the house on the stand rest of the equip soaking in vinegar in the garage. Canopy sitting on sawhorses waiting a rebuild Might be a good time to redo the sump and order a new pump.

This sound more like old tank syndrom hydrogen sulfide rather than palytoxine. Hydrogen sulfide does have a rotten egg smell. This gas was probably what was making you sick.

Palys will have sand stuck to them and have a gritty texture on their "necks", Zoas won't and have a smooth texture. It has nothing to do with size of polyp.

Only problem that I have ( took my H2S Alive coarse a few years ago ) is I remember that the rotten egg smell "weant away" quickly. Really it is your sense of smell being destroyed, but I think that was at extremely high doses which makes sense as a small fish wouldn't create a high dose of H2S as compared to an oil rig blowout.

It's not really the dead fish that created it, it's more the 4" deep sand bed that was black with anaerobic pockets for many years collecting organic matter.

Some people's bodies are more predisposed to certain toxins
 

You are very welcome and glad things are better