Why does the weight Weight of water in dialysis tubing changes over time?

The weight of water in dialysis tubing changes over time due to osmosis, where water moves across the semi-permeable membrane in response to concentration gradients. If the solution outside the tubing is more concentrated (hypertonic), water will exit the tubing to balance concentrations, resulting in weight loss. Conversely, if the external solution is less concentrated (hypotonic), water will enter the tubing, increasing its weight. This dynamic continues until equilibrium is reached or until the dialysis process is stopped.