How do I naturally lower soil pH??

I have 6 pots 3 are different soil than the other 3 and one set of 3 from build a soil is reading 6.2 and the other 3 is reading 7 ish!!!

Reading how?

Organic material and elemental sulfur can help lower soil pH. If you want to flush out some extra Ca, citric acid will help. I use all kinds of stuff from BAS. The Craft Blend has quite a bit of Ca, and my water already has some Ca, so I've been watering with citric acid occasionally to balance it out.

I was testing runoff awhile ago and noticed it was getting higher than I wanted so I watered with citric acid water. The runoff from the more acidic water had a higher pH than regular water, so that's when I figured out what was happening. The citric acid bonds with some Ca particles and gets released from the soil. So you can kinda flush out some Ca if you want with citric acid. The Ca content is what makes the pH wanna rise. It's more about Alkalinity than Ph in a way.

Sulfur