If you introduce new fish into a set up no matter where the fish came from then you are playing a dangerous game.
The need for proper quarantining is said over and over again on this forum and gets totally ignored.
New fish dont just bring parasites into a system but also strains of bacteria that your old fish will have no immunity to.
My advice and i had hoped others would have mentioned it is to get a ten gallon and use it strictly as a quarantine tank for a month to make sure theres no parasites or bacteria present. A month may be a long time, but most diseases take a long time to show.
The need for proper quarantining is said over and over again on this forum and gets totally ignored.
New fish dont just bring parasites into a system but also strains of bacteria that your old fish will have no immunity to.
My advice and i had hoped others would have mentioned it is to get a ten gallon and use it strictly as a quarantine tank for a month to make sure theres no parasites or bacteria present. A month may be a long time, but most diseases take a long time to show.