smoking joe needs help please

hi whats up.i have some indica plants id believe that they are in there 2 week of flowering i see a huge amount of pistols ill get to the point im a newb. my ph is at 8 i now that it not good how can i lower it the easyiest way.i am outdoor growing in northern us great lakes area.i feed 20/20/20 should i change now that it is flowering time if so what what should i use to get the best yeild and how often .
by the way im using 10 gallon buckets. id be glad to post some pics if someone could tell me how not the best with computer.thanks for taking time to help... time to smoke a big faty thanks peace......:bigjoint: