5 to 10 cm/sec.

15 to 30 cm/sec.

15 to 30 cm/minute

15 to 30 cm/hour

B

2B

4B

8B

500 to 750 litres/hour/ m2

1000 to 1250 litres/hour/ m2

1250 to 1500 litres/hour/m2

1500 to 2000 litres/hour/m2

10 to 25

50

75

100

depth of tank

surface area of tank

both depth and surface area of tank

none of the above