Cleaning period for a slow sand filter is taken as -

[Dnyan Deshmukh]

Cleaning period for a slow sand filter is taken as -

(a) 1 hour to 3 hours

(b) 1 day to 3 days

(c) 1 week to 3 weeks

(d) 1 month to 3 months.

The correct Answer Is
(d) 1 month to 3 months