Saltwater fish deaths

Question
Hello Sir
I have had my 55 Gallon salt water fish only tank now for about 4 months. I had the normal spikes in the begining. Everything senttled down and was going fine. The past weekend I went away and was gone for three days. I had some one feed my fish and left exact directions and portions on feeding. I came back to find 6 dead fish and the last 3 died scince. I tested the tank when I got home. the nitrite were about .5. I did about a 12 gallon water change and tested the Nitrites again and it was ok but the last 3 died anyway. Now .5 I know is high but is it high enough to kill all my fish in 3 days? And by the way I have a star fish that is still alive. I have 2 Aqua clear 70 filters, a HOT Magnum 350, a Sea Clone 100 protien skimmer and a Eco Aqualizer acting as a UV steralizer. I also use Kent Nitrazorb in my filters. Any ideas why? Please I dont want to give up on the saltwater tank but I cant affaord to keep loosing hundreds of dollars in fish!

Answer
The nitrite level could have come from the dead fish in the tank, excess feeding and/or a reduction in your biological filter.

Either way, I would be surprised if the nitrite level was what actually killed your fish.  If that was the case the sea star would have dissolved a long time ago.  Sounds to me like there was some sort of contaminent that got into the water or a parasite (inverts are immune to parasitic infections).

That being said, I wouldn't add any fish for another week and potentially do another small water change.  Monitor your levels and look at getting some hardy species to restock with.

Keep me posted as to what happens.

Best of luck!

Regards,
Scott Johnson
Aquarium Crazy Fish
www.aquariumcrazyfish.com