Marine Fish Diagnosis

[Ania]

I have been cycling a 75gal marine tank for about a month now, and one of my cardinals is sick. The flesh at the base of his tail is rotting away. I think it may be tail rot, but I'm not sure.


Is it contagious? How should I treat it?

The sick fish

And a healthy one

 

[Ania]

And tankmates include 10 or so assorted damsels, 2 cleaning shrimp and a crab.

 

[kdrun76]

That is a lot of biomass for an uncycled tank. How are the ammonia and nitrites?

 

[Ania]

Just checked

Nitrate is at 0
Ammonia is at .5 to 1.0

 

[kdrun76]

a full month and you still have ammonia? Yipes. I figured the nitrates were zero, you said you were cycling. Its the nitrites I asked about. Do you know them?