RTC gill curl

So I've got a baby red tail. Currently about 5" in a 135g grow out with a 11" rtc/tsn hybrid, 2x 10" leopard sailfin plecos and a 12" FL spotted gar. Filtration is a 50g sump with 1800gph pump. Black diamond sand substrate, minimal plants and decorations including a hidey hole log.

So I noticed a couple days ago one of his gills is starting to curl. Some quick research showed half say it's a common deformity, half say it's a health problem. Which is it? What can I do to fix it if it is a health risk. If its purely cosmetic I can deal with it, but I want him to be healthy so he can grow big and strong and eat me.

I've got 2 air stones in there on top of having 2 of the output nozzles agitating the water surface, so aeration is definitely not a problem.

I check water parameters usually once a week using API master test kit. Last test showed ph around 6.8, ammonia and nitrite at 0. I usually don't ever bother testing nitrates but once a month because I have live plants and keep up with regular 40% weekly water changes so unless I start seeing algae, I know my nitrates are at least below 60 if not lower. Plus I'm less worried about them because they are MUCH less harmful. (duh)

He definitely didn't come with it. I'm most certainly not going to trim his gill! Who would do that!?

Thanks for the advice. Hopefully he'll get better eventually. It's hard to track the healing seeing as he hides in his log all day.

Oh yeah he comes out for food. But I only feed after lights out so it's hard to tell. Plus the little bugger is so fast!

Is it possible fighting with a pleco about the same size could cause it?