usually once people are able to utilize a scope it is used to determine ripening/degradation so one can plan to start conditioning the buds for consumption.the point im trying to make is once you know the plant has 2 or less weeks left you want to start winding down on the fertilizer.some use flush solutions,some dont flush at all.one thing i can vouch for though is you dont want your freshly trimmed buds to have a fishy undertone partnered with crackle/fizz action.its hard to give an informed decision without pictures but if its foxtailing i imagine shes rather towards the end.good luck man,im in no way speaking as an an expert this is just my opinion from experience.
pics would help if possible