Go ahead and add the acid.

As far as the polyquat and HEDP go -- get what you need NOW, locally. Don't wait. Use Amazon for additional purchases.

I've been testing the API tests, and other aquarium tests. So far, tests from different companies don't produce the same results, so I'm going to need to buy a Taylor ammonia kit ($$) to find out if any of the aquarium tests are trustworthy.

As far as pH goes, you may need to use a meter. I don't recommend it, unless is necessary, since meters are both more expensive and more complicated. But if you can't distinguish oranges and pinks, a meter is your only option. See this thread:
Do I Need a pH Meter? (Am I Color Blind?)