Table 4: Variables selected for turbidity using multilayer perceptrons.

RoundVariablesCorrelation coefficient (C)

1Aluminium dose0.56
2Intake from the pikkala reservoir0.66
3Turbidity of raw water0.70
4Proportion of Lake Humaljärvi/Pikkala reservoir water intake0.75
5Water temperature0.75
6KMnO4 of raw water0.76
7Flocculation pH0.77
8Intake from Lake Humaljärvi0.78
9KMnO4 of raw water0.76
10pH of raw water0.77