Discosoma sp. died :-(

I didn't have time to update this, so I'll do it now. This Discosoma mushroom colony died suddenly. I wasn't sure what it was, but after researching abit I have figured out the culprit. The Euphyllia coral is know to release toxic substances in accordance to fight other corals. No other corals have suffered, but this one. And Discosoma was the hardiest coral I grow!! One could prevent this from happening by using Active Carbon which can absorb the lethal substance but I didn't know this back then.