Black spots & torn fins on Purple Firefish

[MLDTReef]

My purple firefish started developing these black spot marks on its fins. I have not found anything yet on the net that could fit a possible disease and believe this is caused rubbing on the rock due to the tight space he sleeps in the night. Can somebody help on whether I should start any treatment on this or not? I have not seen any aggression signs from his tank mates 2 osc. clowns and a 6 line wrasse. The tank is a IM fission 20g bare bottom SPS dominant and LPS tank running for 15 months. Parameters are stable.

 

[najer]

Bump, @ReefSquad @Jay Hemdal @vetteguy53081 ?

I don't know about diseases, don't rule out aggression if you have a 6 line in 20 G.

 

[Jay Hemdal Verified Community Expert]

Can you get a photo taken under white light? The blue light tinge obscures the details/colors of the lesions.

I agree with @najer - that 6 line could be the culprit. Unlike most aggressive fish, these guys are sneaky, and you won't likely see it happen - over in a second and then not repeated for hours or days. With other fish, like damsels, you see pretty much constant bullying that is easier to identify.

Jay

 

[vetteguy53081]

Expanding the photos, it appears to be Nipping from what I believe as Jay mentioned- 6 line being the culprit.
I dont believe it is a rot by water quality BUT please post your levels for:
Ammonia
Nitrate
salinity
Tank Temp

One little trick you can also do as Jay is again correct as to the sneakiness of the 6 line, set up your cell phone on camera mode and video record your tank for 20-30 minutes and review afterwards and see if the 6 line was indeed the cause. You do not want to be at tank as the fish know your presence and will be on their BEST behavior

 

[MLDTReef]

Expanding the photos, it appears to be Nipping from what I believe as Jay mentioned- 6 line being the culprit.
I dont believe it is a rot by water quality BUT please post your levels for:
Ammonia
Nitrate
salinity
Tank Temp

One little trick you can also do as Jay is again correct as to the sneakiness of the 6 line, set up your cell phone on camera mode and video record your tank for 20-30 minutes and review afterwards and see if the 6 line was indeed the cause. You do not want to be at tank as the fish know your presence and will be on their BEST behavior

Thanks for the responses until now. I have been monitoring the behavior of the 6 line on a daily basis since I have been working from homeH4 is 0ppm NO3 0.2 ppm with Salifert, Salinity is 1.025SG and Temp is 25C. Other parameters are PH is 8.2, Alkalinity is 8.2dKH, Ca is 420ppm, PO4 is 10ppb.

The 6line is a model citizen in the tank, the cleaner shrimp I have is the most aggressive thing in the tank.

The firefish was a late addition to the tank and is in there for a month. I did rearrange the rockscape slightly to help with possible aggression.

I managed to get a couple of photos of it even though not the best quality since it likes to move a lot....