"...I tried to store water in empty soda bottles that were washed out really well. No matter if I boiled it first or not, eventually there was a black mold type thing growing in every bottle. I am not sure if it was the bottle or the water but it really didn't matter because I wouldn't drink it. After all that work of filling and storing bottles, I had no water to drink/cook with had an emergency arise. (I get storms in summer and winter so I need to be prepared year round for spans of time being without water.) I bought the 55 gal. barrel and this Water Preserver. Now, problem is solved and I am happy to know I have usable water." -- Actual 2015 WaterPreserver^tm Five Star customer review!