Hello Waiakeauka. I'm not sure if this will help you or not but i found this on another website and it made sense to me -
Cannabis requires a 1:2 ratio of P to K throughout all stages of it's growth.
It's worth stating for the record the actual ratios of N, P and K that cannabis requires through it's life cycle:
Vegetative Stage
N - P - K
3 - 1 - 2
Flowering Stage
N - P - K
1 - 1 - 2
Final Flowering Stage
N - P - K
0 - 1 - 2
To translate this into a 12 week schedule for a typical Skunk type such as Cheese or Psychosis would give something along these lines:
Veg week 1: 3 - 1 - 2
Veg week 2: 3 - 1 - 2
Flo week 1 : 3 - 1 - 2
Flo week 2 : 3 - 1 - 2
Flo week 3 : 1 - 1 - 2
Flo week 4 : 1 - 1 - 2
Flo week 5 : 1 - 1 - 2
Flo week 6 : 1 - 1 - 2
Flo week 7 : 0 - 1 - 2
Flo week 8 : 0 - 1 - 2
Flo week 9 : 0 - 0 - 0
Flo week 10: 0 - 0 - 0
This schedule reduces the Nitrogen two weeks into the 12/12 period which will assist in stopping the vertical growth (stretch). It cuts out all Nitrogen after 6 weeks which will result in a less leafy, smoother burning end product with greater density to the flowers. The last two weeks of plain water is sufficient to leach out all accumulated salts and give a clean end product. Three week flush as advocated by some really isn't necessary if the Nitrogen is cut out after 6 weeks. The people using a three week flush tend to use Canna nutes which have too much N in them for late flowering and this is why they get a benefit from flushing for three weeks.
Hope that makes sense. Despite all the crap the nute companies fill our heads with about the need for all kinds of fancy bottles, you really don't need any of them. Cannabis is a simple plant, a weed in fact, and all it needs is the correct NPK at the correct time plus a full range of trace elements, that is hard fact and no amount of BS an marketing from the nute companies will ever change that fact.
Anyway
Hope this helps you a little bit ? Good luck and Happy Growing