What a week! First; I nearly, if not did, destroy my oldest plant growing in dirt by putting water with vineger in it to bring the PH down in the hydro grow. Now I check the PH in the hydro and it's in the 7's. Being a bit leary, I did however add water with vineger in it to the bubbler.

How long after adding vineger should it take for the PH to come down?

Here's a pic of them at day 7