Shower enclosure leaking
Check and make sure the leak is coming from the bottom sometimes water will run down the panels and the side collecting at the bottom. As for as sealer I always use bath and tub caulk it is designed for use in wet areas and resist mildew.  I use blue painters tape for a nice clean line and so I can work the caulk making sure I have a good bond remember to remove tape while the caulking is still wet.