WHOA! Do not go dumping meds in a tank with a gold nugget for that sort of a spot. The odds are good it's either a wear spot from wedging under decor (that IS the high spot on his back) or he's burned it a little on your heater while desperately searching for some cover. It's a common problem and definitely not something you want to just treat indiscriminately. Most ich meds severely affect your filtration bacteria. Dosing them for anything but what they're designed for is just taking a huge risk, especially with a fish that can be extremely sensitive to ammonia or nitrite.
If he was mine, I'd net him and carefully swab a little bit of iodine on the injury. That will kill any bacteria and give his system a chance to heal it, without risking your water quality. It's how I have treated dozens of pleco injuries, up to and including after removing part of a fin to rid a fish of a large tumor. It works great and is way less traumatic in the long run. Pimafix and Melafix won't hurt anything, but probably aren't necessary. Keep an eye on the spot. If it grows or looks inflammed then you'll need to treat him with a broad spectrum antibiotic to treat the secondary bacterial infection, but the odds are good it won't require that, if the fish is healthy in the first place.
Barbie
If he was mine, I'd net him and carefully swab a little bit of iodine on the injury. That will kill any bacteria and give his system a chance to heal it, without risking your water quality. It's how I have treated dozens of pleco injuries, up to and including after removing part of a fin to rid a fish of a large tumor. It works great and is way less traumatic in the long run. Pimafix and Melafix won't hurt anything, but probably aren't necessary. Keep an eye on the spot. If it grows or looks inflammed then you'll need to treat him with a broad spectrum antibiotic to treat the secondary bacterial infection, but the odds are good it won't require that, if the fish is healthy in the first place.
Barbie
