Abstract: A tube coupling device includes a coupling member having a lower casing and an upper housing and a peripheral flange extended between the casing and the housing, a water guide plate is engaged into the housing and has one or more off-center passages, a partition member is engaged in the housing and includes a pathway for the water to flow from the water guide plate and into the casing, and the partition member includes an inclined inner peripheral surface formed around an upper recess for defining an inner peripheral projection and for engaging with the water guide plate and for anchoring and retaining the water guide plate in the housing, a receptacle is engaged in the casing for preventing the materials in the coupling member from being released into the water.