I dont think you need to add anything...i think fox farms got it correct i have had no ph issues no issues what so ever and the drainage is on point....the only problem would be someone who didnt get that foxfarm was packed with food for tha long run, with patience and the following of instructions fox farm should work for anyone....also im using miracle gro once a week and slowly increasing the dosage 5 bucks from Loews...i think fox farms has gud soil but all that feeding schedule shit seems fishy to me it seems like marketing(too many different bottles and shit like that) and i wont bite jus like i trust foxfarms with tha soil i trust miracle grow in getting it right when it comes to nutes...grow on!!!!!