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A third peristaltic pump was added to the system to provide a pump from the stock solution of lime slurry to the tubing that flows to each apparatus. The tubing for the A1 pump and the A2 pump met the tubing leaving the third peristaltic pump with as little tubing in between as possible. This was done in order to minimize the amount of lime that might be able to settle out in the tubing. There was tubing attached to the stock concentration bucket (approximately 5 gallons) and then split to run through two separate pump heads on the third peristaltic pump (Figure 1). Because the pump had to run at only one speed (380 mL/min to add the lime slurry as quickly as possible) there had to be two different tubing sizes running through the two pump heads in order to accommodate for the difference in pulse volume needed for A1 and A2. The tubing sizes were determined to be 17 for A1 and 18 for A2. Calculations can be seen here: 
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A2 performed similarly to A1, except that it reached a level pH of approximately 11.5 much more quickly. It started failing sooner than A1, at around 6:00 am, only 18 hours after the experiment began.
Figure 1 2 - Experiment 7