Usually in Malaysia, when ...

Usually in Malaysia, when turbidity is high which is more than 500NTU, what we need to look at is the optimization of coagulant dose (Liquid Alum, PACl and ACH). If primary coagulant is not enough for the flocs  to settling down, then coagulant aid is needed. Coagulant aid is a polymer usually polyacrylamide. There are many types of polyacrylamide (charge, molecular weight, etc). Then, we need to look on the sizing of your sedimentation tank retention time. Study on this 1. Coagulant and coagulant aid 2. Sedimentation time 3. Water quality when conducting test. Use Jar Test to determine this first, then only conduct for a plant trial.