Hi - Just had 1st hot tub delivered and shortly after came across this site - very interested in the approach advocated here and have learned some so far - though much more to learn. Regarding how to get started - I did receive a starter kit that I used out of the gate though haven't been successful balancing water yet. I used a bottle of metal control and a bottle of ph reducer as well as small amounts of Dichlor. Question - do I need to empty / refill tub before adopting the TFP method or can I just shift to that - tub was filled on 6/6? Thanks in advance for your counsel!