Run off PH off the charts

I am having some leaf curling on most of my new babies (about 12 or so). I figured it was bad PH. I PH every drop of water that gets dripped on the plants. PH has been running 6.6-6.8. I decided to test the run off after watering a 1/2 dozen of them and it was 5.5. I am using Root Organics. I just ran 6.6 water through the soil mix. In 5 seconds I had enough run-off to test it....Again 5.5 coming out. I opened 5 more bags of soil mix and it came back exactly the same 5.5. Is it possible the PH of the soil is that low and why? All of my early leaves are curling and looking really dry. Otherwise I think I might be over watering although the soil a couple of inches down seems so dry. When I feel into the planters through the drain holes it seems just a little damper than it does straight out of the bag...

How big are the pots? Are they curling up or down? and looking dry is usually something with PH or underwatering or nute prob. probably due to PH problem locking the nutes out. try and bring that run off to at least 6.3-6.8

I have photos....I just turned the HPS back on. I turned the temps in the room down from 77-85 to 75-82. I have ballast in the room and the fan still only comes on for a minute or 2 every hour. Humidity, I am not sure...I would guess 60% give or take 40% LOL. I thought perhaps my PH pen was out of whack. When I went to the website, I realized I had purchased a top of the line hand held meter & only being a week old, should be pretty accurate.
In the last hour I have read on one forum or another that the Root Organics reads low coming out for the sake of some thriving fungi that is added or is there naturally, yada yada yada. Because I transplanted yesterday I did lightly water them, when I otherwise wouldn't have, but the problem pre-exists the recent overwatering.
I will post some pics of the sicker looking seedlings. New growth looks wonderful. I have 600W HPS about 18 inches over the tallest plant (I ran out of veg room after transplanting so I stuck the A/F's in there with a couple of Laughing Buddah I want to clone from (if they stretch, no problem I am cutting anyway). Hand test I can hardly feel the light at all. The 250MH feels hotter. I have it a few inches higher yet. T-5" are 2-3 inches above bulb.
I may have overwatered at least once before.
Leaves are turning up and some twisted which I think is PH issue. I am also using PHed distilled water, TDS under 20PPM. Maybe I ought to just PH the well water and get some disolved minerals into the mix. I figured that any nute difficiencies would appear so soon, especailly given the reviews about Root Organics.
The pots are 4 gallon, except for Auto Flowers in 2 gallon pots. Outdoor strains in red pots. All of this started though while they were in cups.