GH test measures calcium and magnesium. Many critters (fish, shrimp, snails) have specific requirements for GH in a certain range. If you have white crusty stuff around the sink then you probably have high GH, also called hard water. The other clue is the plants that are thriving for you. Most plants will grow under a wide range of parameters, but some plants thrive with higher mineral levels.
KH test measures the carbonates and bicarbonates. Some plants can use the carbonates as a source of carbon, so, again, the plants that are thriving for you suggests the KH is up there a bit. KH also acts like a buffer to stabilize the pH. Usually if the KH is high the pH will be high and difficult to change. If the KH is low then the pH could be anywhere, and is easily changed. pH or 7.4 is not very high. Suggests a moderate level of KH.
To raise the GH I use Seachem Equilibrium. Other GH boosters are out there, but read the label. Make sure they do not have salt (sodium chloride).
To raise the KH I use potassium bicarbonate. You can also use baking soda.
Before you do anything, get a hardness test and test both of these values.
KH test measures the carbonates and bicarbonates. Some plants can use the carbonates as a source of carbon, so, again, the plants that are thriving for you suggests the KH is up there a bit. KH also acts like a buffer to stabilize the pH. Usually if the KH is high the pH will be high and difficult to change. If the KH is low then the pH could be anywhere, and is easily changed. pH or 7.4 is not very high. Suggests a moderate level of KH.
To raise the GH I use Seachem Equilibrium. Other GH boosters are out there, but read the label. Make sure they do not have salt (sodium chloride).
To raise the KH I use potassium bicarbonate. You can also use baking soda.
Before you do anything, get a hardness test and test both of these values.