What's best NPK for making seeds?
I figured with a screen name like greeenfireseeds... that would be considered a silly question? ;8^D
the key is really just to take the plant a couple extra weeks into flower...
so you may keep feeding nitrogen and your micro nutes a week or so longer than normal for that strain IF that plant typically finishes very drained of nutes, to make sure there is enough nutrients to produce the maximum amount of healthy viable seeds possible.
also feed flowering nutes for an extra week or so...
but as far as NPK and dosage they stay the same... just a couple extra feedings because they will have a higher nutrient "burden" (if you will) because of all the seeds as well as be flowered for a longer period of time and therefor need more nutrients to keep them from becoming deficient before most the seeds have fully matured... it also seems that you don't want to much nitrogen late in flowering for the seeds sake also (I've noticed they can take longer to mature and the seed shells are much harder for the tap root to break... when fed to much nitro in flower and kept to green til harvest)