Hey, sorry to hear your having such problems, i had a hard time with ulcers. i used PP and got some meds to use as a bath from the vets.
Potassium permanganate & peroxide, used to treat ulcers in koi & goldfish.
You will need:
Peroxide (available at chemists)
Potassium Permanganate (available at chemists)
This is better done with 2 people, one to hold the fish above the pond/tank (in case fishy gets dropped) one to administer.
Swab the ulcer (using a cotton bud) with a dab of peroxide, to get rid of the nastiness etc. then (*pre prepared) cover with a thin layer of the PP. be VERY careful not to get the peroxide or PP in or near the gills. This treatment is ONLY used for body wounds. Anything near gills/eyes (not on them) use an iodine swab instead and no PP.
*to prepare PP put a small amount of PP in a clean tub (as I only had 2 fish to do I used a medicine measuring cup) mix with a few drops of water to make a thick paste.
The PP will have a purple tinge to it, and the peroxide WILL fizz when used ? don?t panic. Some of the PP will come of when the fish is put back in the water, but hopefully it should still be okay. It may look an odd brown/black colour for a few days. It?s okay. And remember it takes a long time to heal ? you won?t see over night miracles.
This treatment is only to be done once. PP can do as much harm as it can good.