Drinking water treatment at Morton Jaffray Water Treatment Works in Harare faced challenges due to pollution from Lake Chivero. Researchers tested five coagulants to replace alum, a traditional chemical. Primco 100 performed the best, needing the lowest dosage compared to alum. The other coagulants tested did not affect the water's pH significantly. This study suggests that Primco 100 could be a good alternative to alum for treating water at Morton Jaffray Water Treatment Works.