fertilizer for mother plants

Anyone know what to use. I planted them in Miracle-gro pre mixed soil w/ fertilizer about 6 months ago. some of the leaves are yellowing and falling off. Nothing too big of a deal. What about for flowering SOG style? Any recommendations?

I cut(trim) the root-ball and re-pot that soil is spent and dangerous after 6 months.

Hmmm.. Would I actually cut some of the roots off? Or just shake them free? Is the miracle-gro soil with the fertilizer decent? And why do you say it's dangerous?
Thanks

I cut the roots trimming the top at the same time. Or get a good clone and start her over.

As for fertilizer I have some organic stuff...North country I think. All the numbers are below 5. Would that be good to use as a fertilizer?

I use Epsoma plantone...That is the only fert I recommend by name

Is this an organic fertilizer?