Tank Crashing

[luvmytang2]

This is my first post....need help, please!
My sw tank is approx 4 months old. Everything has gone pretty well with a few minor exceptions until.....my blue tang got ich. I have a few corals and was advised by my lfs to treat with a reef safe (organic) ich treatment. This did absolutly no good. I finally QT the tang and used copper, but it was too late and he died.
A few days later I purchased a replacement filter pad for my tank. A few hours later....everything including my inverts and coral looked TERRIBLE!!!. I immediatly removed the filter pad and the following day did a 30% water change. While the corals and inverts have improved back to their normal appearance, I have lost all of my fish. One by one. I called the LFS and was told the filter came from their store that caught fire a few days ago. Yikes!!!! I also want to mention that a few fish were also starting to show early signs of ich.
I did another water change today....this time about 20%. I need help. Can someone share with me their opinion. Do you think the filter pad killed my fish or did I have more ich than my fish could handle? I am just confused because the corals and inverts have pulled through while ALL of my fish are dead.
What do I need to do? Thanks for anyone who can help.
Tank: 75 gallons
temp: 78
nitrite 0
nitrate: trace
ammonia: 0
PH 8.3
calcium 480
alk 4.8
salinity 1.023

 

[jlem]

Do nothing for the next few weeks at least. Don't use copper and quarantine all of your fish when you decide to restock. Don't listen to the LFS. No matter how helpful the store is they are there to make money and there is a whole lot more experience here on the board than at any fish store.

 

[luvmytang2]

So would you say my water is toxic from the filter pad or did Ich kill everything?

 

[birdy]

well the big question is if you saw ich on all the fish that died. Also when you started loosing fish did you test the water? Did you have some high levels? The filter pad certainly sounds like it contributed to the problem, this is probably one of those things where you will never know the true reason, it is most likely a little bit of everything.
My advice to you now would be to keep the tank free of fish for at LEAST 4 wks (I usually do 6wks to be safe). This will kill off any remaining ich parasites, then QT any new fish for 3wks, to be absolutely sure you are not introducing ich back into the tank you would have to put all new fish through Hyposalinty treatment, but not many people are willing to do that.
Your levels look good, you might want to increase your salinity a bit (sg of 1.025 for inverts and corals).
I would just keep doing water changes weekly and then when the 4-6wks is up start restocking slowly.

 

[luvmytang2]

I checked my water immediatly when I noticed a change in my tank. I also have checked all levels each day since this has happened. The levels have remained the same with the exception of the Nitrates....they were at zero when I first checked and then today I only find a trace.
I only had about 7 fish with 5 showing signs of Ich and the others not. I know I have been told by a previous reply not to listen to the LFS....trust me I will NEVER do that again. When I went back today and explained my situation. They told me to empty the entire tank and start over.