FAQ: Will Seachem Flourish Advance® affect my pH, GH, or KH?

No.  Flourish Advance® contains neither buffers nor significant concentrations of calcium and magnesium, so it will have no impact on pH, GH, or KH when used as recommended.   If you have laboratory-grade equipment, you may note a slight increase in calcium and magnesium (these are included in the product as essential minerals for plants) but they are not present in high enough concentrations to show up on a standard GH test kit even when grossly overdosed.