Treatment water contained a natural, 100- or 1000-fold increased sediment concentration in the experimental vessels (340 ml glass beakers) of the corals C. huinayensis, to which they were exposed during the periods between water changes (2-3 d). Using a turbidimeter (2100Qis, Hach Lange GmbH, Düsseldorf, Germany), the turbidity of the treatment water was measured every day and twice a day when a water change took place (just before and after the water change). The mean values from the bulk samples (ten vessels per concentration; bulk sample of water from five vessels of one concentration = one sample; per concentration = two samples) were calculated and are shown in the table, as well as the standard deviation.