What does betta fish fin rot look like?

Answer:
There is a whiteish edge to the fins and a thinning or threading of the joining tissue between the fins rays. The condition can only be fixed by the proper use of a cycled filter and cleaning up the water with regular 50% water changes every week.
First answer by EddyJ. Last edit by EddyJ. Contributor trust: 132 [recommend contributor recommended]. Question popularity: 1 [recommend question].