Yup, mix and leave in the frig...The water I just place in the draw next to the frig...Been doing it this same way since starting.
The HGH protocol has been played around with throughout the years and I have always ended up back at right before bed...But the way I handle the actual product hasn't changed at all.
BUT again, I have always said that I was not a good example of what to do in this game...Just stating I have never had a purity issue, or any noticeable negative effects...Not a chemist so have no clue the growth rate of bacteria or the effects of which it would play into the use of HGH?!