Hello I am doing said quest and I've fill the initiate's Ewer but I can't fill the basin in Auriel's temple, my map marker is on the basin but when I press the action key nothing happens. I've refilled at all 5 places turned off all mods etc but nothing seems to work anyone have ideas to fix it? I have even tried to advance the stage but the door wont open...

I remember reading before that sometimes it gets bugged if you don't do the shrines in a certain order

Try reloading from before darkfall passage and doing the shrines in the EXACT order listed here:
http://www.rarityguide.com/articles/articles/2908/1/Skyrim-Dawnguard-Walkthrough-Dawnguard-Side-Part-13-Wayshrine-Locations/Page1.html

Something must have known this would happen because I have a save right before entering...I'll return to tell if that fixes it.

Well collecting them in that order worked for me this time around thanks!