How much use do you get before you need...
How much use do you get before you need to replace the filter? (I didn't see this in other reviews or the info. Sorry if it's already been covered and I didn't see it).
Depends on the quality of water you're filtering to begin with and how often you back flush the cartridge. Running silty crap through it might give you only a few gallons, but under considerably better conditions, you should expect about 1500 liters or somewhere just south of that. I've used a MSR Autoflow gravity type filter system (also Cascade Designs) for a couple of years now and I'm absolutely thrilled and impressed by how easy, efficient and effective it's been. Bottom line: you won't be disappointed!