You can make your own sodium citrate if you can't find it or run out and need some. Here is the recipe (formula) that makes 11 grams, mix 8 (7.96) grams of citric acid and 9.5 (9.48) grams of sodium bicarbonate (baking soda) then add to your liquid. It will foam and after the foam subsides the liquid will contain about 11 grams of SC. If you want to make SC and save it here are the ratios, for every 2.1 grams of citric acid, use 2.5 grams of sodium bicarbonate in a little water, this ratio will yield about 2.9 grams of SC. Then on medium heat evaporate off the water and the remaining powder left in the pan is sodium citrate. It's just chemistry.