I have googled double glazing windows filling with water, but didn't find such an epic failure as my office window.
I think its been heated during the day and cooling at night drawing water into a tiny pin prick. I'll probably never find where it comes in. Still I thought someone might appreciate the failure. I'll replace it later in the year but fir now its anyones guess how high it will get.
I could completely fill it up that would be cool.