The slurry was filled up to 80% volume of the funnel. The volume (V) of the filtrate collected in a 250 ml graduated measuring cylinder, was recorded at regular time intervals (Δt). The end of the filtration phase is attained when the points in the Δt/ΔV versus V plot deviates from the straight line. The force balance for the gravity filtration using a filter paper on a Buechner funnel can be written as shown by Mahesh et al.