That's not true. People who used AquaSoil reported that their pHs' fell to 4.5, but this also depends on their original tap water's pH/kH. Chia, AquaSoil simply replaces the Mg and Ca in the water, which leads to lower the pH/gH.turtlehead said:most substrates buffer so it allows the plants to have easier acess to the nutrients and its beneficial. and it wont buffer that much so it doesnt really matter.
On the other hand, Turface Grey *was* the ideal substrate. Good CEC, porous, and it had more nutrients than Flourite/Onyx.