Welcome H-G,
You have chosen a picky and hard strain to grow! but one that really gives you some strong medicine in thee end. I have grown purple kush for about 2 years straight now and it is definetly a growers private stash!. They are very picky when it comes to feeding them so be careful and feed them on the light side. I use Advanced nutrients-sensi bloom a & b 2 part soulution nutes. Its a killer company that tests their product's on MJ. Another great company is Botanicare, they have great prices and products to choose from. You should be able to find these at your local hydro shop if you have one. If your growing in soil i recomend Fox Farm's Ocean's forrest! Its pretty much ready right out of the bag, its a great organic soil and if you use it you wont need to feed your plants for the first 2 or 3 weeks of growth. The last 2 weeks I use some M.O.A.B(mother of all blooms) to puff things up, remember to give them at least a week of nothing but pure p.h balanced water tho to flush out all the chemicals and nutrients. I recommend either Clearex by botanicare or Final FluSh by Advanced Nutrients to use for flushing your plants properly. This will dramaticaly increase your taste and smell, and even help your herb burn better to. If you can post some pictures up here and will do the best to help you out. Peace and Love!!!
Roken.