I've used the Moritz Kidney tea a few times but to be honest I'm not sure putting the correct ratio of herbs (3 tbsp's) to water? The instructions with the herbs doesn't say the ideal amount of water, preferably in onces. I do soak the herbs over night but it might still be too weak if I'm putting too much water in! Seem to rememeber the instructions saying two cups... How much is an american cup??