Mollie In Need Of Help?

[ntrueman]

Hi all! Hope you can help...

Over the past several days one of my 4 mollies has developed what I can only describe as a yellow "tip" on it's dorsal fin. I've not seen anything like this before so really dont know what to do? It's not acting strangely and seems to be eating/moving well, I had a small case of fin rot in the tank about 2 months ago but I cleared that up without using any meds in about 2 weeks.


Tank stats from less than 10 mins ago:
Ammonia: 0
Nitrite: 0
Nitrate: 13
PH: 7.6
Temp: 26.8c

Picture below shows the offending mollie and fin!

 

[airbusa1]

The fish is just maturing you will eventually find the whole edge of the fin to be like that soon. Dont worry.