Neon dwarf rainbowfish fins not fanned out

[Foxstar]

I have recently noticed that one of my neon dwarf rainbowfish side fins are not fanning out at all. They are less than one year old. The fish is still swimming around and acting like normal. does anyone know why this would be happening?


I have a 55 gallon tank with 2 three spot gouramis, 6 nd rainbowfish, 2 cory cats, and a bn pleco, and a lot of plants.

 

[Autumnsky]

Hi!

How long has the tank been set up, and are these Rainbow fish new to the tank how long?

Do you know about the nitrification cycle, if not check the AA article in my signature link. very full of information about tank and fish keeping in general and good to read!



What are your water parameters?

Ammonia
NitrIte
Nitrate
pH

Temp

KH/GH

TDS

If you do not have a test kit, please do a series of water changes.

Save a sample 1/2-1 cup, to take to a store BEFORE the water changes for comparison.

 

[Autumnsky]

You can do a series of pwc's, one right after the other 25%, and the reason is to get the new water and the older tank water to change gradually and be easier on the fish

And after a couple to 8 hours, another pwc back to back. and then see if the fish is looking and acting better.