Yup, I bet the STS is taking over and removing KH. KH is totally crashed and pH is at the bottom of the chart. Added 2 tablespoons baking soda; this ought to raise the KH by about 4 German degrees of hardness, and bring the pH up a bit.
I realize that baking soda will raise the dKH, and I use an online calculator
to determine the amount of baking soda to add to accomplish the desired change.
How were you able to determine the dGH (General / German) change that would occur by adding the two tablespoons of baking soda?
Last edited by Seattle_Aquarist; 09-08-2012 at 04:35 PM.
Reason: added link