Neat idea but i wouldn't gravity water. There are quite a few cons people don't realize on these. Drinking straight: Most time you gotta bend down or get a container to sip from and takes SO much pressure to suck from it. Drinking from a bag or bottle: Same as above but also you sometimes put pressure on squeezing the bag and this sometimes can likely puncher the bag or rip as some might squeeze to hard to get enough flow. Plus the fact that now you're aiming down (putting the bottle to the air) ALL the dirty water sediment now drool into the filter FIRST. Instead of the first deal where all the dirty stuff doesn't float and sinks to the bottom. Unless it's super light like a leaf. But most of that is avoided since your straw is under that top floating layer. Gravity filling: This goes similar to drinking from a bag or bottle. Due to the fact that you have to 'Hang' the bag and let the water drool down into a clean bottle/etc. All the heavy sediment hits the filter location FIRST and you end up getting to clogged. And it takes quite bit of time depending on such. Using a pump would be the best choice. As in your last piece of the video you can use the flex as a First attack resort by hooking the inlet dirty water hose to the drinking piece and using that to suction fresh water into the pump and then the pump's inner filter will do even more filtering. This would give a better cleaner result and since the lifestraw flex will float mostly. That'll make it not pick up most of the sediment on the ground to clog up;. Or you could do similar to a electric pump version that would suction much faster and give you water easier. They do sell some rather cheap motors that can hook up to these kinds of self contained filters and be used like a person sucking from the clean end. Expect it's powered and faster. Also for 4:35. The normal lifestraw Flex came with a rubber collapsible squeeze system bottle that the flex screws into the top and it basically acts like a squeezable water bottle. But they don't sell this sadly now and only sell Just the flex as a replacement cartridge. I have the OG and it came with the squeeze bottle.

Great review! Just bought one... seems better than most others

Nice review on the Lifestraw Flex Filter! The threads you were wondering about screw into a 22 oz collapsible squeeze bottle (which may be discontinued by Lifestraw now - I'm not sure).

How’s water tests? Or it’ll only clean it ?