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Once the FCM was set up and the bottles were attached to the PVC and connected to each other with the appropriately calculated lengths of tube, we measured the resulting flow rates to determine whether the calculations had been accurate. (The intended flow rates were 100 mL/min for the clay and 5 mL/min for the alum when the tubes were both plugged into the middle hole on the inflow column.) We found that the clay flow rate was a little bit too fastabout 120 mL/min, and so we increased the tube length and measured the actual flow rate by hand until we had a flow rate as close as possible to 100 mL/min. The final tube length was 146 cm. The alum flow rate was a little bit too slow with the design length of tubing, so the tube was cut to 75 cm, where we measured the flow rate by hand to be 5 mL/min. These results were interesting because they implied that in the case of the larger diameter tube, the head loss equation over-estimated the head loss in the tube, and in the case of the smaller diameter tube, the equation under-estimated the head loss in the tube.