Well you have the correct pen. Remember to measure the medium you poke the hole with the probe cover, then insert the probe. Always store the probe with the KCL solution.
I simply use an offset feed, you get instant results as the pH swings thru the Goldilocks zone. So if the medium tests at 5.0 and you are aiming for 6.5 (-1.5) then I mix a feed at +1.5 or 8.0. It could be plain tap water "feed" you will get a lot of calcium precipitate if you have a feed but I do anyway.
The pH will swing down between the corrective feed and the next, ending up a little low but not nearly as low as it was to begin with. Then you can do a smaller corrective feed.
Once you get the swing down to a reasonable level say 0.5 then I like to feed a little high and let it swing thru the goldilocks zone each feed. So say feed at 6.8 and end up at 6.3.
I did a little write up on correction
Checking and adjusting the pH of your root zone in soil or coco is a very important part of growing healthy plants. Often you will notice nutrient deficiencies despite the fact you know you have provided an ample feed at an appropriate pH level. When this happens it’s generally either...
www.rollitup.org
