Okay then, I stand corrected!I don't think so. Alk is KH or carbonate hardness and GH is general hardness. GH measures divalent metal ions (Ca and Mg) and KH specifically measures carbonates. You could have a non-carbonate source of Ca and Mg that would show up in GH but not KH. For example, my tap has about 3 dGH and 1.5 dKH. They're definitely different. For planted tanks you want low KH and medium GH.
An actual chemist would know the difference between the two better than me.