I did some calculations over here:
Let me try simplifying, using Precision Hydration as the example:
- PH 500 packet has 250mg sodium per 16 ounce / 455ml bottle
- PH 1000 packet has 500mg sodium per 16 ounce / 455ml bottle
- PH 1500 packet has 750mg sodium per 16 ounce / 455ml bottle
(somewhat confusingly, the nutrition info on PH website is for 32 ounces but the mixing instructions are for 16 ounces, so the nutrition info is for 2 packets and 2 bottles)
Lets call those low, medium, and high.
1 gram of sodium citrate (trisodium citrate anhydrous) has 267mg sodium
- Low: add 1 gram of sodium citrate for 267mg sodium per bottle
- Medium: add 2 grams of sodium citrate for 534mg sodium per bottle
- High: add 3 grams of sodium citrate for 801mg sodium per bottle