[gremlin]

If I have a bag of JI Seed (low fertiliser) and JI No 3 (high fertilizer) what proportions would I  have to mix them to get JI No1, JI No 2 etc. 

Not meant to be an exam question    Only looking for a general idea

I got fed up at the end of each year having bags of half used Seed, No 1, No 2, No 3 etc.
I generally take about half and half plus bit of sharp sand, or whatever I had for luck, to make an unscientific potting on compost that not too strong.

[mumofstig]

the conductivity guide here
http://www.johninnes.info/technical.htm

should help you with working out the ratio. required 

[gremlin]

Thanks.

So half and half JI Seed plus JI No3 is near enough to JI No 1 1/2  for me !