...
In order to test the calcium carbonate hypothesis developed by the Fall 2009 team, the Spring 2010 team ran a second experiment to compare the performance of the reactors using distilled water versus tap water. There should be no carbonates present in the distilled water, so if the formation of calcium carbonate precipitate inhibiting dissolution is what is limiting the reactor's performance, the use of distilled water should produce better results. The two runs in this experiment were identical except for the water type so that that variable could be isolated.
...
The team used the same procedure described on the materials and methods page. The lime was added as dry powder. For the up-flow rate of 120 ml/minvelocity of 3.6 mm/sec, it was calculated that 20g of lime were required for the effluent to be saturated for 12 hours.
...