Yup organic/aluminum free sodium bicarbonate(baking soda)..i found mine in the organic aisle in ACME, or Wholefoods market sells it for like a few dollars, alkaline water is great for overall health anyway/making the PH in your body higher, and since we are ALL on a high protein diet, try to add an organic salad to two of your protein meals. Easy, cheap, no cooking/steaming. Raw broccoli, arugula, Kale, spinach, some organic olive oil and red wine vinegar, or fresh squeezed lemon, and you counter the acidid nature of this diet. You can see if its working by buying some PH strips and checking your PH first thing on the morning. If its over 7.1, you are fine. Drink alkaline water till you bust! If you buy a case of it at Wholefoods Market(its cheaper than you think), they will give you 10% off.
Just my 2 cents......this is what i am currently doing. PH the other day was a very alkaline 7.4, and thats on 300 grams protein/day.