I have had the Stratum now for about a little more than a month (between cycling the tank, numerous water changes and a couple of weeks with shrimp) - so I can't speak to how well the buffering of the soil lasts. I use RO/DI water with Salty Shrimp GH+. My pH has been steady at about 6.7 (using calibrated digital pH meter). I also have driftwood, Indian Almond Leaves and Alder Cones in the tank. I do like the looks of the Stratum but it is very light - sometimes a pain to secure plants into the substrate. But the plants seem to be doing well (low tech type plants like anubias, jave ferns, buce and mosses - also some S. repens in the foreground).