is it hard to get off? if so i got a couple tricks up my sleeve i detail cars for a living. a lot of people over the years come in with water spots on their window like that. its just the built up minerals in the water. we have to explain to them that they have a sprinkler system in their yard causing it. EVERY person that has came in and had hard water spots has a sprinkler system. The way we remove it from glass is semi easy...

Materials needed:

1. steel wool
2. wet rag
3. water (spray bottle or bowl to dip rag in)

make sure the glass is WET before you rub steel wool on it or it WILL scratch your glass.

basically you just keep wetting the glass and rubbing it with the steel wool.

im new to vivariums so try this on a small spot first and see how it works. there seems to be no chemical i can find to get it off. steel wool works best for me.

also...ive never had build up on my walls. because i do not use tap water. ONLY tap water has done this to me. any bottled water i used has worked perfect.

use bottled spring water and purified water.