I would get a bottle with a built in filter. Only drawback is you would have to change the filter but you can also use it for outdoor stuff. I have one of these I keep in my bug out bag and it works great.
http://www.rei.com/product/799021/katadyn-mybottle-water-purifier
This is prob more what your looking for though.
http://www.rei.com/product/799021/katadyn-mybottle-water-purifier