Inclusion Criteria:  18 years of age or older Received a kidney transplant in the last four weeks Potassium < 4.8 at time of randomization (not having high potassium already) History of hemodialysis dependency (and not peritoneal dialysis) prior to kidney transplant Able to provide informed consent Not currently consuming a high-watermelon diet or taking co-enzyme Q10 Not underweight (body mass index <19 kg/m2) Receiving standard immunosuppression regimen (mycophenolate, and tacrolimus) Not enrolled in any other interventional trial Planning to return for follow-up at UCSF (or willing to return for study visits)  Exclusion Criteria:  < 18 years of age at the time of transplant Potassium >=4.8 meq/L at randomization History of peritoneal dialysis dependency or preemptive transplantation Unable to provide informed consent