Help!

[shauna]

OK, here's the background. I have an established 75 gallon tank, readings always great, never any problems whatsoever. Tank inhabitants were:
Porcupine Puffer
3 False Percula Clowns
Potter Angel
Chocolate Chip Star
Hermit Crabs
Snails
Last weekend my husband went to LFS and bought a Blue Hippo Tang. It was acclimated and then placed in the tank. A couple days after placement I noticed my tank was a little cloudy, tested the water, everything was fine. Yesterday I notice my starfish looks a little sickly so I pulled him from the tank. I went to sleep last night and wake up to find everything is dead with the exception of snails, hermit crabs and coral!

Could this LFS bought fish brought a disease to my tank? I can't figure it out. Also, I'm kind of at a loss as to what I should do now... Should I move the coral, snails and hermits to another tank and completely drain the water from my 75 gallon?

 

[shauna]

I should also note that all the fish were fine. I had fed them yesterday evening, they were actively swimming as usual. They looked fine as well.

 

[jackri]

Have you tested your water again? And by fine when you did test what were those numbers and what tests were they?
Sounds like something in the tank the tests couldn't pick up though.

 

[shauna]

PH @ 8.0
Ammonia @0.0
Nitrite @0.0
Nitrate@ 10
Salinity @ 1.023
tank stays at 78 degrees

 

[sean48183]

Did you put your hands in the tank with maybe moisturizer or soap on them. Cloudy water is usually from that or the substrate getting kicked up. Did your skimmer go nuts? If it did then there was a foreign substance introduced to the tank. What about Caulerpa? Do you keep any of that? Can go asexual and make a mess of the tank.

 

[shauna]

I do use lotion, but as far as I know I haven't put my hands in with lotion on. I'm usually pretty careful about that. When I woke up this morning the tank was a lot cloudier with dead fish, all inverts still alive. I really can't figure out what could have happened. The only thing I could figure is that the new fish had something to do with it since it happened so soon after adding it. There haven't been any other additions to my tank for awhile now. Should I remove all the water and start from scratch? And no caulerpa in tank.

 

[blue oasis]

I was told that if a puffer fish should die it will release toxins into the water that might kill the other fish, that is why I will never but a puffer fish.

 

[sean48183]

I don't believe puffers release toxins. That is just if you eat it. I think box fish do. Are you running a skimmer right now? Let your skimmer run a few days then do a 50% water change and you should be back in business. Always wash your hands with just plain warm water before you stick them in the tank.

 

[shauna]

Yes... running a skimmer. I will try what you said. Thanks

 

[gmann1139]

I'm not sure that what happened is 'old tank syndrome', where a skimmer could have prevented it. It does kind of sound like it, but the timing is kind of strange. If a new fish was just introduced, I think you always have to assume that was the problem unless proven otherwise.
I think the new fish brought 'something in', and that something ended up killing all of the fish. Either that or it was harrassing something (like the starfish), and some type of toxin was released.
I would get a skimmer, and perform a large water change, but I would also start running carbon, and leave your tank fallow for 3-4 weeks, in case there is something in there.