I think my fish have fin rot

I noticed 2 days ago that the fins of my one damsel had white tips, and it seemed to be having trouble swimming. The fins were not all there at that point, as the tips were missing. Today, it was having more problems swimming, and has died an hour or so ago. I examined my other damsel and it also appears to have white tips on its fins as well.

Is this fin rot, and if so, how is it treated? It's super hard to get a picture as this little damsel hides in the rocks all the time.

 

Good luck getting a straight answer on this one. I had the same question on about Yellow Tang

 

What other tank inhabitants do you have ?

Is it possible these injuries are the result of bullying ?

Fin rot usually does not progress that quickly, nor lead to the fishes demise that quickly. If you have damels I would question if they are causing issues and stressing other fish as well.

Most common cause of fin rot is physical abuse by another fish resulting in a bacterial infection setting in. IMO.

 

My cycle just completed 2 weeks ago with all levels at 0, so I added a Three-stripe Damsel and Yellowtail Damsel. The only other things I have are a Turbo Snail, 2 Blue-leg Hermit Crabs, and a few snails that hitched a ride on my chaeto. The damsels have not nipped at each other when I was watching (which is quite a lot).

The Yellowtail hid almost all the time in the rock shown in the photo below. I included it because of the dark growth on it, which appeared approx. 2 weeks ago. The Turbo Snail cleaned it all up one night but it was back within a day or so. I wasn't sure if this growth was related.

For the record my parameters are:

PH: 8.0
Ammonia: 0
Nitrite: 0
Nitrates: 20

The nitrates puzzle me as a week or so ago they were nearly 0.

Here is a photo of the growth on my rock. It is on a few others, just not as bad as this:

 

I gotta go with bullying and less than ideal water conditions. Those are the two primary reasons for fin rot. Even though you have not seen nipping I am willing to bet that it is happening at night.

You can treat fin rot in a hospital tank with antibiotics. But I am guessing if you do a water change, do not get any more damsels and add livestock very slowly to a new tank it will resolve.

Damsels are aggressive no two ways about it, especially the black and white strips and dominos (three spot).

 

the rock is covered in a diatom bloom. it will subside once the silicates in the water are all used up (usually after two or so months)

The deaths are just due to the tank being so new still. most likely some parasites and fungi that have rode in on the live rock and are still thriving. just give your cycle a little more time to level out their numbers... If you purchased the fish from petco, a large part of their fish (99%) are infected with who knows what and die within a few days.

Come up to that pet place this saturday for the frag swap. First, their stuff is generally in acceptable healthy condition and second, they have everything 25% off this saturday only

 

Would this bloom effect my nitrates? As I said they were close to 0 a week or so ago, and now at 20.

 

there is a slight die off from the plankton and other microorganisms... however its usually not a big deal.
What kinda flow do you have through your rocks? like koralias or circulator pumps