And another label:
1400mg for 1 teaspoon
Five estimates per teaspoon are:
- 1000mg rough estimate
- 1326mg from trisodium citrate data using anhydrous density and anhydrous molecular weight
- 1400 mg from Judee’s Sodium Citrate label
- 1165mg from trisodium citrate with anhydrous density and dihydrate molecular weight
- 1168mg from Modernist Pantry label
Calling @redlude97 to review! 
Not a big deal, just curious.
Yesterday I opened the Pure Ingredients branded sodium citrate, added one teaspoon to a water bottle an hour before going out in 102F / 39C heat. Looking closely at Precision Hydration and recalled that info is confusing. One packet of PH1500 is roughly 750mg sodium, 125mg potassium, 24mg calcium, and 12mg magnesium.