@tacticalbelle: I personally like the gravity system because you have the option to just stick the straw into the water source and drink straight from it…or you can setup the gravity bag and use it for the whole family to fill their water bottles. 📌 Note: Obviously, the amount of time it lasts varies based on how dirty the water is and how much water you personally drink, cook with, etc. per day…but this should give you a good idea of what you’re working with. The more you know. 🧠 #membranesolutions #waterfilter #emegencypreparedness #survival #camping @Membrane Solutions