well I am not sure ?? someone with more exp will know tho , but in the meantime you could put some perlite in a cup and run some water thru it and check the ph and see. I'm betting its micro nutes in the soil .. goodluck
veggii Reviewed by veggii on . How does perlite effect PH? I probably have a very simple question. Here's some background info. My Amish friend has some babies in 16oz keg cups, they look great, and are still in the "seedling" stage of life. All is well, however, when watering with RO water, adjusted to 6.8, (and even down to 6.7) the ph of the runoff still comes out at roughly 7.2-7.28? The soil is foxfarm lightwarrior, and the very bottom inch or two is solid perlite. (Hoping to aide drainage although the fflw is very light and seems pretty Rating: 5