We like to drink sparkling mineral water and were buying a couple of cases of 6 liter and a half bottles each week - more in the summer. Apart from the weight and pain of lugging them up, they're not a very good thing for the environment. Also the water in Rome is remarkably good, it actually tastes good. So when we saw this "soda stream" gadget in a local dept store we decided to buy it - expensive but we paid it back in a couple of months with the savings from the bubbly mineral water we would buy. However there's a problem. I know plastic bottles are not good to keep water in, or to reuse. These say they have a two year life span and then have to be changed. But i noticed that after several months they begin to smell - not sure what of, but just not right. We rinse them out every time, wash occasionally with detergent and recently have been washing with bicarbonate of soda and vinegar. I remember reading somewhere that you shouldn't reuse plastic store-bought mineral water bottles or to refill them, and the plastic bottles used in water coolers are not supposed to be refilled. would it be better to have the glass ones and am i taking any risks with the plastic?