You have it turned up too high. Empty your cup. Plug your hose in the far air hose plug. Wait for the unit (bottom part to fill up to the O ring). Now move your hose to the inner plug. Adjust your flow valve to where you see bubbles at the O ring but do not turn it higher. You should see foam coming out of the top by morning.
I played with mine last night and turned it up too high somehow. This morning the room was flooded with 6 gallons of water. thought my tank had sprung a leak but the cup overflowed and started trickling on the carpet....what a way to start my day....