Complete wipeout

[Dianeags]

Within 48 hours I had a complete wipeout except for my starfish. I have a 300 gal tank with a u /v, protein skimmer. I also have an r/o system, and chemi- pure

I brought a sample of water into all fish and results were perfect except. For nitrates which were 60.

I waited 4 weeks then added 3 new fish and they all died within 2 days

Any help would be greatly appreciated

[Brookster123]

Marine velvet is the only thing I've heard capable of that rate of devastation.i have no sw experience, just based on threads in this forumn.

[Mebbid]

Marine velvet takes a little bit to kill fish. Certainly more than two days. I would suspect this is an issue with a contaminant. Is there any remote possibility of any chemicals that could have gotten in the tank?

[carey]

Actually, velvet kills in about 24 hours. I know from experience with it twice. :-(

That also is the only thing off the top of my head that could have caused a complete wipeout in a short amount of time.

That and like stated above, something thast got into the water.

How old is the tank and what exactly was in it?