So my tanks with ADA Africana substrate have been running for about 3 weeks now. I use RO/DI water for these tanks. I just received my pH digital meter and calibrated it, then double checked. I then tested the pH of the water with the africana and it's reading 6.8, my RO/DI water is also reading 6.8 pH.
I was told that this substrate buffers the water around 5.5. Did I get a bad bag of Africana? What are everyone else's experiences with this substrate?