Hopefully, you have a pH meter.
Measure the pH of your water AFTER you add all of your nutrients and mix it up well. If you need to pH up or down, use an eye dropper or pipette to add DROPS not splashes at a time until you get it where you'd like it.
Add say 4-6 drops and mix your water well and wait to see where the pH changes to. If it's still not where you want it, add another few drops and again, mix well and wait to see what the pH meter reads.