Hi … I am growing autoflowers in living soil indoors. I checked the ph of my soil with a meter and it read 7ph. Thinking this may be in error i made a slurry with 1 cup soil and 1/2 cup of 6.6ph distilled water. The slurry registered a 7ph on my meter. Thinking this may be in error i squeezed the water out of soil through a coffee filter and used my liquid ph meter ( which i calibrated and tested just before this test) and the squeezed out water from the slurry was at 5.8ph. so, i have no idea what my actual soil ph is. While i am not currently thinking i have a ph problem, i’m not sure how to accurately check it, should a problem arise, flower cycle has just started. Should i average the difference between soil and runoff and settle at 6.4ph or so? … or what?
If you’re using living soil, the soil will take care of the PH. I’ve been using Living Soil for a while now and just put aerated tap water in it and they grow just fine. No need to measure PH or PPMs or any of that. Just water and add some compost and teas as needed.
Also with living soil you don’t water to runoff. Very different than running soil with nutes. You wanna keep the soil fairly moist throughout the grow. This means you do not do the flood to drought method of watering.
Thank you for your reply.
I guess i am just paranoid about my wildly different ph readings (i"m a bit of a control freak it seems) The water comes out of my distiller at 6.6ph, i will just continue to use that and try not to lose any sleep!
THANKS AGAIN!
Yeah living soil is a totally different beast. Took me a minute to get used to not checking things out as much. But long as your soil is healthy your ladies will be too.
To answer your question about how to measure the pH…
Your slurry method will do it. Just check the pH of the strained water from the slurry. 
It appears that your soil pH is about 5.8+/-. I am not suggesting any action here. Just attempting to answer the question.
Thanks for the reply.
I think I may worry too much. I’m determined to make organic living soil work for me.
You will get there. Plenty of folks here to help out.