i bought the betta along with 5 other guppies, and after taking them home, i realised the guppies all had columnaris, so i think the betta also had columnaris because i think the petshop had one main filter for all of the tanks, so all the fish there must have it. anyway by the next morning after getting the fish, all of them had died. i know for a fact that the guppies had columnaris due to having all of the symptoms, i am currently treating my guppy and platy tank because of this infection, they seem to be getting better so fingers crossed!
the water conditions were actually very good for the betta at my home, so i know it had not come from me. unfortunately im unable to give readings because i threw away the test strips last week after he died.