The water direction of travel in the sand filter is a vertic

The water direction of travel in the sand filter is a. vertical (up) b. vertical (down) c. horizontal (downstream) d. horizontal (upstream)

Answer:- All options are correct. The flow of water in sand filter can be vertical (up) . It can be vertical (down) in vertical filter. The flow of water can be horizontal in horizontal sand filter. Flow of water in sand filter can be vertical or horizontal both.