A liquid treatment method includes mixing a liquid with an agent to form a mixture, aging the mixture to obtain to a predetermined condition in at least one of the liquid and the agent, and dispensing the aged mixture. An interaction between the liquid and the agent causes the predetermined condition to occur. Also, a majority of the aging occurs while the mixture is in a dynamic state. A related system includes a mixer receiving a liquid and a drag reducing agent and an aging module connected to the mixer. The mixer disperses the drag reducing agent in the liquid to form a mixture and the aging module has a flow path along which the mixture flows. The flow path has a distance sufficient for a majority of the aging to occur while the mixture is in a dynamic state, wherein the aging changes the drag reducing agent to a predetermined condition.