I don't like to see members spending money for test kits they will only use once...can you not get the GH from your municipal water authority, on their website probably? Once you know the number, we're set.Ok, just saw your post, i will return the clown, the shark and the angel, buy the 5 gal. For my betta and spend money on a test kit to find out water hardness. I have well water in western nc. I do have a large piece of wood in the tank, does that affect hardness of water?
Wood like all organics (fish excrement, uneaten food, dead plant leaves, dried leaves, peat, wood) has a tendency to soften water, but this is limited by the initial GH, the KH or Alkalinity, and the pH. Lowering pH goes along with lowering GH/KH.