Those "coloured skirt tetras" are really white skirts who are dyed. They won't live very long, and they need a school of 6 (if you get more, get regular white skirts, not dyed). The dying shortens their lifespan dramatically and makes them far more prone to illness. It's animal cruelty that isn't seen that way.
The only way you could have betta(s) in there is if the barbs, skirts and serpaes were gone (all very nippy), and if you got either 1 male or 3+ females. 2 males/1 male 1 female will fight, usually ending in a dead or near-death betta. With 2 females, the dominant one would pick on the subordinant.
so bettas are out of the question. i believe my cycle is done after 2 weeks of nitrites, both nitrites and ammonia is 0ppm and nitrates are at 15ppm it only has been 2 days of no nitrites. i wait another week before add some more fish. i am looking for two eye catching fish along with another set of schooling fish. I was think tiger barbs but i do not want another set nippers. any ideas guys
30gl
6 serpae
3 color skirt tetras ( will add 3 more white skirt)
Are you planning on getting more white skirts (non-dyed)? You should take them back or make them a school if you're going to keep them. For now, seeing your plans, they're taking up valuable space.