mini tank crash....palythoa toxin the cause???

[daniella3d]

It does not need much in a small tank to cause RTN and a chain reaction to kill coral, especialy such sensitive coral as sps and elegance. A 20 gallon tank can get unbalanced very fast and that can lead to some major problems.

It can be anything, a PH swing, salinity raise, ammonia peak etc.

When you put that rock in, did you remove water or did you just put it in? if so then I suppose that you water line was much higher and the evaporated water did not get replace thus rising the salinity fast. Just a guess here.

It could be from the coral sliming but I doubt that would have killed the invertabrate. One of my friend had her anemone cought in a pump and that released a lot of toxin in the water as the anemone shread into pieces. All fish died but none of the invertabrates were affected.