Planted Tank Enthusiast
Join Date: May 2019
Location: Palm Springs, CA
So if a high CEC substrate like STS lowers the pH (and presumably the KH as well) of hard water, how long does this effect last? Presumably you'd get an initial big drop while cycling the tank, but then what? Once the STS has reached saturation with calcium ions, does the pH & hardness then go back to whatever those levels are in the water you use? And how long does that take?
I'm starting a new tank with an organic peat potting soil covered with STS, and what to know what to expect. Don't want to be stressing my fish or plants with drastic swings, nor do I want to invest in fish or plants that prefer low pH/low hardness if it's just going to eventually go back up the high pH & hardness of my tap water. (I know I could use RO, but I'm trying to keep things simple & cheap)