I use a Neti pot for my sinuses and it works great. I usually use tap water which is technically a no no but recently there have been a few cases of parasites killing people from using tap water. I could be a normal person and buy gallon jugs of distilled water or boil my own water but why do that if I can use a simple sport bottle water filter to filter the water first. I have a Berky sport bottle I could use but I am saving those for BOB's so I was thinking about just getting a Brita bottle filter like they sell at Wal-Mart. So does anyone know the smallest size particle they will filter and what size would be needed to filter parasites, virus, ect?