Choose a lower corner of the frames to drill through the tarpaulin and wood a hole of diameter slightly smaller than the diameter of the tube you have. This tube will be forced into the hole and through a patch in air chamber which has the role of making a tight connection between the pipe and the cover (the hole drilled in the air chamber is much smaller than the tube, that is forced back into the air chamber). The patch will be glued to the tarpaulin with neoprene glue. The two pipes thus fixed to the frame will open into the freshwater recovery bottle. We will take care to make a hole in the cap of this bottle to allow a good flow. Both pipes pass through the cap. Plan to secure the two tubes to avoid pulling on the inner tube patches while handling the desalinator.