Peat is not necessary, To lower hardness adding an acid like lactic or citric would work too. Even phosphoric acid or if your daring stronger acids like HCL. Acid + Carbonate = Co2 + H2O. Its up to you to figure out the chemistry of it though, should be simple search online for some tables or an equation.
I have the test kits that test both KH and GH. I follow the instruction and have found out that the KH is quite low but the GH is very high. Instructions are followed very closely, so there would be no mistake here (I am a chemistry major and have done those kinds of chemical tests very often).
What is the problem here? Does it mean that the carbonate concentration is low, and magnesium and calcium concentrations are high?
If you take the KH value, then your water is quite soft. However, if you take the GH value, then the water is very hard. What should I take, KH or GH or both?
On liveaquaria.com, when they sell fish, they often include the KH (no GH) range that is best suitable for the fish. If we just depend on KH, how about the GH? Are we gonna ignore it?