MG organic soil. What is the PH?

The contents are 50-55% composted bark, sphagnum peat moss, pasteurized poultry litter, and wetting agent. I am guessing because of the bark and moss the ph is rather low. I have no way to test the soil PH, but I can test my water PH. If plants are showing signs of low PH should I be watering with water that is a bit higher than 6.5-6.8?

I would not adjust it until I knew. Dolomite in organics is good. The MG organics needs it to grow MJ>

Test the runoff water. That should give you an idea of what the soil pH is.