The main taste of this soup should lean toward the sourness followed by the sweetness. Fish sauce & salt are here to help balance the taste not to over power the other two. So in order to make the best soup, you should never use more than the recommended amount of fish sauce. If you need to adjust the saltiness, always use extra plain salt. Because too much fish sauce can compromise the main tamarind taste. Remember a little seasoning goes a long way, adjust with a few pinch salt or sugar at a time. Wait for them to dissolve completely, taste, then add more if necessary.