That's what I've been told. I am no scientist. What I was told was that glass is porous and that glass is actually an extremly slow moving liquid. I am a home inspector so I have exp with window glass. Don't know if there are different grades of glass for aquariums. In old windows, the glass becomes thicker on the bottom than the top. That is the glass very slowly following gravity. I have told that certain chemicals can seep through the glass. Chemical molecules can be much smaller than water molecules. I don't personally know if that is true, but it makes sense if glass is a liquid. Also all aquarists make sure that there is no cross contamination with any form of cleaning products. Why would Windex be ok?
I have added a couple links that also back this.
www.nutricraze.com/Article_about_How-to-clean-an-aquarium-a-3982.html
http://www.ehow.com/how_3260_clean-aquarium.html
http://aquaria.net/articles/glass/cleaning/
I have added a couple links that also back this.
www.nutricraze.com/Article_about_How-to-clean-an-aquarium-a-3982.html
http://www.ehow.com/how_3260_clean-aquarium.html
http://aquaria.net/articles/glass/cleaning/