is fin rot contageous?
i just bought a koi over the weekend, didn't quarantine it. Big mistake... (i know i know...but whats done is done...need to rectify, time)
introduced it to the pond and noticed the fin was deteriorating pretty quickly...first day it was slightly discoloured (white fins of a Kohaku)
today it was missing a very small section at the end and appears to be eating away.
anyhow, I've refunded my money at the koi seller... but what should i do with the rest of the water?
should i put additives/treatments to disinfect the water? the rest of the koi appear to be unaffected and healthy.
or should i do a complete water change?