A vacuum head for a rotary cleaning head is disclosed that has a vacuum port arm defining a vacuum port, and a vacuum slot arm defining a vacuum slot. The vacuum head may be L-shaped, its vacuum port may extend along a radius of the rotary cleaning head, and its vacuum slot may extend in the direction of rotation of the rotary cleaning head. The vacuum slot receives vacuum from the vacuum port, and is operable to vacuum up at least most of any cleaning fluid that collects on the leading side of the vacuum head, to prevent that cleaning fluid from being slung outwardly from the rotary cleaning head. The leading side of the vacuum port arm and the leading end of the vacuum slot arm may be tapered to help the vacuum head ski up and over any fixed obstacles it encounters.