Sherlock Holmes anyone ?

[Buccaneer]

Ok ... here is what happened so far ...
had a nuisance algae on sandbed so wife and I decided to vacuum it off ...
mixed up 30 Gallons of water to replace the siphoned water and went to work ...
in vacuuming I got a little too close to my LTA and " cleaned " a few tentacles by accident ... he seemed OK and today is just fine ( this was last nite )
siphoned sand was cleaned and returned to tank
almost finished returning sand to tank and noticed the green chromis acting weird and panting ... within minutes all five were dead
then my firefish ... same thing ... gone
then my shrimp ... 4 cleaners / 2 peppermint and a Coral banded shrimp ( had the CBS for 4 years )

My CBB , Foxface, Sailfin Blenny and Yellow Tang are all fine

Tested Nitrite / Nitrate / ammonia ... all zero
PH 8.2
temp 82
SG 1.025

Now the potential problems ...
Tiger Tail cuke ... have not seen him but that is not unusual as he can go hiding in the rocks for days at a time ... also supposedly non-lethal cuke ?
Foxface ... venomous but why pick on 5 GC and all the shrimp ?
Refugium ... maybe a macro went asexual ??? ... read somewhere on RC that it can be toxic if it happens ???
siphoned too deep ? ... maybe I siphoned too deep but would'nt it show up on the tests ?
LTA ... does not give off a poison of any kind does it ?


If anyone has any ideas then let me know

Cheers