Bingo, your soil is a little low.
Huh, I never saw that kit before. The one I'm used to is the GH one, bottle of liquid that actually reads in closer intervals. VERY VERY accurate, for a liquid test. It's VERY cheap and you should pick one up next time you are at the hydro shop.. you have to go there anyway to get some plant pH up.
Was that a liquid or one of those pellet things that you can only use once? ecause I see some crud in the bottom of the tube. But at least you know what your problem was! (Rhizome is always right BTW! It's his superhero skill- infallibility in matters of horticulture, lol!!!)
Okay, the way that I would deal with this if I were you would be to pick up some pH UP and using your test kit, make up a gallon of solution to flush with that actually reads 7.0- on that kit, green. Make the solution very carefully, add SLOOOWLY, almost drop by drop, stopping the moment it turns green. This is called titrating to the endpoint, the endpoint being your chosen pH.
You can use this solution to pour through your soil. Catch the runoff of that soil drench and test THAT. It should not be green any more.
Adjusting soil pH is an art. And you are about to become freaking Van Gogh. (Ear surgeon skillz not required)