Flame Tetras aggression

[prcy]

Hey all, new member here.

I've found myself with a dilemma with two potential solutions in regards to fin-nipping and aggressive chasing between fish. I have an individual flame tetra that seems to school better with my x-rays and shows particular aggression against the other flame tetras that aren't in hiding to avoid the chasing. This fish has a much shorter and rounder body and deeper orange compared to the others, I'm not sure whether this would suggest a female?? What would the community advise... removing the problematic fish and hoping the hostility subsides or adding a further school of 4 - 6 to potentially form a tighter school of it's own species?

My tank is stocked as follows:

35 gallons (tall)
12 x X-Ray Tetra
1 x Bristlenose Pleco
5 x Flame Tetra
8 - 12 x Ramshorn Snails (by choice)

(AqAdvisor: Your aquarium filtration capacity for above selected species is 284%)

Many thanks, all

( EDIT: ) all my water parameters are in a good range (ammonia and nitrites at 0), other than the water hardness (HARD) which is a local issue where I live.

[Delapool]

Imo I'd remove if possible, then go for a larger school. I find problem fish tend to stay problem fish unfortunately. I do find though that larger schools above 10 seem to be a lot better behaved and more natural.