lol...
What you do... You test your solution with a pH meter goofy.
Take your pH 7 water, add your nutrients, and then test the pH. If it isn't 5.5ish then you need to add small amounts of pH up or pH down products to get it there. Work slowly, don't overcompensate, adding both up and down to a reservoir is a bad idea (bicarbonates and phosphoric acids don't mix well in a high salt solution).
Then you take this solution and allow it to rest for at least 6 hours, IMO, 12 hours is about right. You should run a small water pump (Petco, like $3) to circulate the water. Air stones will skew the solution pH. Check the solution every few hours and adjust as you need to. Usually the pH of the solution will rise over time, so don't be hasty with the pH up. You can also just add plain 7 pH water to get the pH up a little bit instead of bicarbonates.
That's basically it. Mix, test, balance, rest, test, balance, rest, test, balance, and apply.
I really recommend TechnaFlora pH down as your controller. They use Nitric Acid which is more stable in an aerated hydroponics setup. You'll want to test the pH of the reservoir every few hours after adding it. If you need to alter the pH in the rez create a small amount of a water/pH down solution at a pH of 4.0. Add this solution slowly to the reservoir to bring the pH down.
Keep the reservoir pH between 5.4 and 5.8 and you'll be in good shape. Running closer to 5.8 during flowering will help make magnesium available when using high potassium blooming supplements.