The salt paste is a good treatment and could be all that is needed. You will see any infection below the SAP fungus when you scrub the area with the salt paste, and if it is infected and you decide to do injections, then you first need a source for injectible antibiotics, which are hard to come by. Then, my preferred means of injection is to sedate the fish with clove oil or MS-222, then turn the fish over and lift the one of the pelvic fins, and inject in the soft spot, aiming the needle at about a 45 degree angle toward the head. Many instruct shooting through the scales, but the needle will often pull a scale out, where shooting in that soft spot, there are no scales. The other information is contained in the https://www.koiphen.com/forums/showt...ive-Discussion
Zone 7 A/B
Keep your words sweet. You never know when you may have to eat them.
Richard