the fert that i am using dont have any potassium. now i know why my plant has'nt been growing really tall like everyone elses, my fert has 24% nitrogen, 8% phosphate, and 16% soluble potash. everyone else recomends to use a fert with 20-20-20. oh and mine has EDTA(chelating agent)(minimum) 1.2% is that good or bad. and thanks latewood for clarifing that i need high potassium not phosphate.