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The 0.1 cm orifice appeared to clog after 4 hours, indicating that a larger dosing orifice might need to be used. For the Agalteca plant, based off these experimental results, we are recommending increasing the diameter of the smallest dosing orifice to 0.152 cm (0.06 inch) to minimize the occurrence of clogs. In addition, we are recommending using 51 grams/liter stock tank solution, which again should minimize the clogging frequency. The downside to using a lower concentration alum is that the stock tank will have to be changed more frequently, yet this should help with . We will check with the operators in Honduras to ensure that the stock tank turnover rate is compatible with their schedule.
Since lab grade alum was utilized in this experiment and a clog was still present, the presence of foreign material, might not be the main cause of the clogs present in the Honduran plants. An inline strainer might be beneficial to include in future dosing systems but it would be more effective to verify the Honduran operators are cleaning the system regularly and ensuring no foreign matter is making it into the dosing system. Yet it should be noted that this would not eliminate the occurrence of clogs since they may also appear to be caused by the precipitation of aluminum and calcium species in the water.