You have made two erroneous assumptions in Step 2. First, the water doesn't drip onto the open surface of the resin. Second, the water is heavier than the resin due to the salt content.

There is a tube that directs the salt water to the bottom of the resin vat, any turbulence in the salt water/resin interface is contained inside the tube until the bubbles of water exit out of the tube firmly at the bottom of the tank, where they stay.