You want to use this 4-10 days before you harvest so this is something you're going to have to decide. It's a nice window, actually - gives you a bit of flexibility as to when you harvest! Take a look at the trichs and figure out if they need another week or so or if you need to harvest quickly (4 days) ....then mix up a solution and thoroughly soak your pots. Then you wait 6 hours and flush the pots with clear, pH'd water and continue to ONLY give the plants pH'd water until you harvest...
Sounds like you're approaching trim jail! COOL!!!! Good luck....