To explain myself better. The poor support isn't in the wall. It's at the front of the tub that is enclosed with ceramic tile and a step. I have no way of giving it extra support unless I tear up the new ceramic tile enclosure. I imagine your advice is still the same. I'm going to consider your suggestion of using 3M Urethane Marine Sealant. Thanks! Do you think I could remove the old grout, use the Marine Sealant as a filler further down and then grout over top followed with a clear tub and tile caulking? Just so I can maintain a neat appearance? Or does that make no sense at all? Thanks Stew!