Three species of corals. Acropora palmata. Diploria strigosa, and Montastraea annularis. were exposed to the same weight of sediment. Corals weie exposed to sedimeni during day light and darkness. Oxygen production and consumption were measured by respirometery; sediment removed by corals was collected simultaneously. All corals exposed to sediments showed an increase in respiration rate at night and a decrease in net photosynthesis during the day. Lowered net photosynthesis was due to both light shading and respiratory increase. Integrated 24 hour P/R ratios for control and sediment-exposed corals were calculated. All control corals had naturally occurring P/R ratios in excess of 1.0, but the sediment treated corals, without exception, had ratios signficantly below 1.0, mostly due to high respiration during sediment rejection. M. annularis and D. strigosa have very high clearing rates relative to _A. palmata.