1. Patients must be 18 years or older,

2. Have been on dialysis for at least 1 year,

3. Be stable on treatment (i.e., without frequent changes in their dialysis prescription, or recent hospitalizations),

4. Be reasonably nourished (serum albumin \> 3.5 g/dl and not currently receiving oral nutritional supplement through DCI).

5. Self-reported urine output of \<200 cc/day

6. Functioning arteriovenous fistulas or grafts for dialysis access

7. Currently dialyzing at a dialysate \[HCO3-\] of 33-37 mEq/L.

H+ Mobilization With Dialysate Bicarbonate Variation