Two phosphAte taRGets in End-stage Renal Disease Trial (TARGET)

Inclusion Criteria: 1. Age ≥ 18 yrs 2. Receiving chronic hemodialysis for \> 90 days, 3. Dialysis prescription is currently no more than 4 sessions per week and prescribed as 3-5 hrs per session 4. Most recent P value 1.30-2.50 mmol/L 5. Receipt of a calcium-based P binder Exclusion Criteria: 1. Patient is booked (with a known surgical date) for a live donor kidney transplant in the next 26 weeks 2. Planned switch to a dialysis schedule that involves \> 16 hours per week of therapy within the next 26 weeks. 3. Planned switch to peritoneal dialysis within the next 26 weeks 4. Pregnancy 5. Albumin-corrected serum calcium \> 2.60 mmol/L in the past year requiring reduction of the calcium carbonate dose 6. History of calciphylaxis 7. Attending nephrologist believes that an otherwise eligible patient is mandated- on clinical grounds- to have a P value that is targeted to \< 1.50 mmol/L or \> 2.00 mmol/L 8. Attending nephrologist believes an otherwise eligible patient is not a candidate for escalation of the current calcium dose 9. Co-enrollment in a clinical trial where the intervention is deemed to interfere with the adherence, safety or efficacy of the intervention provided herein