This post is annexed to a post I started on treating cyanobacteria and is meant to be a reminder to everyone in here that it's not enough just to simply follow directions from manufacturers but to ask and heed the advice of the people in here who have gone through similar situations, whatever they may be. Here's the post:
Treating cyano question
I did everything according to the instructions on the medication which was pretty straight forward:
"Mix one level spoonful for every 15 gallons of aquarium water with a small amount of water from the aquarium to be treated. Pour dissolved solution into the aquarium. Repeat after 48 hours if necessary. Wait at least one week before additional treatments."
"Note: May affect pH and oxygen levels."
Even the LFS told me that they use this product for their own tanks, it's completely safe for all inhabitants. It may affect pH but this should take care of itself after a day or two.
Saturday morning I mixed my solution, putting 7 spoonfulls for my 120 gallon tank (1 spoonful for every 15 gallons) and poured it in the tank. Shut the skimmer down for the day, left my filter run with no media for added flow.
Sunday morning everything was dead (trigger, tang, puffer, hawkfish, chromis, wrasse). The only survivor was my coral beauty, and my shrimps.
So now I'm starting from square one. The tank has been stripped, everything in it has been thrown out with the exception of the live rock which is now dead. I'm going to keep a couple of pieces, boil them and use some of the rock for decorative purpose on my next setup.
This has really bummed me out. My kids as well. ......but I'm not defeated. I will learn from this and go forward.
Life can really suck sometimes!
Total disaster .... everything gone! 
