i think you can totally up your ppms. my plants are on a 1200-1100 ppm diet and they LOVE it. when i was doing around 800-900 ppms they showed signs of slight defeciencies. i also agree hanna meters are shite. totally utter shite. get a blue lab truncheon ph meter or an oakton meter. also for my feeding schedule this is what i do. my first feeding in flower i do a mix of bloom and grow. half way thorugh my flowering period i do another feeding of a mix of bloom and grow so far my plants really like it.