In our new shower, the gap between the fixed glass panel and glass door is 7/16". The installer is telling us that this is acceptable, but that gap allows water to splash through. He obviously does not want to redo the glass. Is there an industry standard? What is acceptable?
Well, that's a bit bigger a gap than normal.
If you decide to live with it, there are sweeps and L shapes you can attach. One manufacturer is CR Lawrence: CRL shower door wipes and seals
In particular, the one I'd look at is the "CRL Translucent Vinyl Edge 'T' Wipe". Alternately, the PCC10/PCC12 might work for you.