Ragged Pleco Caudal Fin

[Shaucid]

Hello everyone, this morning I noticed my Bristlenose Pleco has a ragged caudal fin, which wasn't there yesterday night.
 
It's quite confusing because the only other fish in the tank is my Opaline Gourami which is diurnal.
 
Can't supply a photo because the pleco won't come out of his bogwood cave.
 
Here's my water stats:
 
Ammonia: 0ppm
 
Nitrite: 0ppm
 
Nitrate: 20ppm
 
PH: 7.6
 
Could it be fin rot?
 
-Thanks.

 

[Gilli]

More likely to be because they squeeze themselves into impossible little niches in the caves and he probably caused himself some damage - mine does the same from time to time. He may have had an argument with the gourami- I also keep 3 spot gouramis and occasionally if the gourami gets in the way of my BN especially at feeding time they have fisticuffs!

 
Water stats look good. Do plenty of 50% waterchages which will help it to heal.