Corrosion cells were refilled with 50 mL of fresh test water according to the experimental design summarized in Table ; this volume was chosen to prevent contact with the sealant while minimizing headspace. We completed 42 changes of water before beginning to collect data, and each change was followed by a minimum 24 hour stagnation period. After conditioning, lead in 0.45 µm filtrate agreed reasonably well with predicted equilibrium lead solubility, with a mean absolute error of 8 µg L -1 at the low level of aluminum, a temperature of 21°C, and either 0 or 1 mg PO4 L -1 .