Trichomes Slow

I have 2 females that are at 6 and 8 weeks, seems predominate sativa....they both have nice buds for CFL grow but trichomes are not showing/developing like the last indica I had ...is this normal...feeding bloom buster 10-52-10 was thinking about going back to 15-30-15...cause it seems I have some nitro shortage. Sorry no pics.

Sativas take longer than Indicas to develop and flower. So, you probably don't have anything to worry about. Just be patient and they'll start showing up.