If Florabase is like Aqua Soil, "buffering" is not the right word.
What happens is that the clay material has a very acidic pH; that means that a large proportion of the CEC (cation exchange capacity) in the clay is occupied by hydrogen ion of aluminum ions. The calcium and magnesium in the water is exchanged for hydrogen on the substrate material. This is a common reaction -- the same reaction used in the cation exchange part of a deionizing water filter. The hydrogen ion is released into the water where it combined with the bicarbonate and lowers the KH. The calcium and magnesium is bound to the substrate particles.
The reaction happens with Aqua Soil, my akadama and probably Florabase also. However, the impact on GH/KH is only temporary. In my experience, there is a drop of about 20-30 ppm. As a result, you need to closely monitor this initially. |