The duration of your treatment is based on two things. It is based on getting your blood clean with each treatment and also removing the fluid weight that you gain between dialysis treatments. If your phosphorus is still high, and you cannot take phosphate binders, then the only other way to remove phosphorus from your blood is with dialysis. The doctors (nephrologists) at the kidney center are ordering the duration of your dialysis based on your monthly chemistries. Hence, I would follow their advice. Another possibility is to consider dialysis at home where you get to design the dialysis around your schedule. I suggest that you ask your physicians about home dialysis.