Issue with opacity

[Mike53]

I seem to have developed another issue, when i change the opacity - modify 3d view - the walls become opaque but not the Room (floor) i was using this to create water for a pool, any suggestions. I am going to export it so i can modify the mtl, if i were told what to change, and what to change it to, or what to add

[Mike53]

[:-/] Totally baffled now, it's working today [:-/]