South Australia is well known for having the most foulest tasting water of any capital city in the country. You can smell the chlorine from quite some distance. Consequently, we've had an inline water filter for the last few years and wouldn't be without it.

The company that provides it offers a great service; they come around once a year and for 60 bucks, check the system and replace the cartridge. To us, it's a cheap price to pay for decent tasting water. I asked one of the guys a couple of years back what they do with the cartridges and it seems they are thrown out - ick; yet another disposable item. There's a fair amount of plastic in those things and it bugs me that the company isn't recycling them (perhaps they are now)..

For folks not under contract with a company for servicing, the same challenge presents itself; chucking out another lump of plastic to join the millions of tons that hits the waste stream each year.

But there's an alternative that can save you a good deal of cash too. Like ink cartridges, some disposable water filter cartridges can be refilled at home, far cheaper than having to buy a new one and you'll lessen your environmental impact as well.

There's a great tutorial on Instructables for refilling disposable Brita water filters - according to the tutorial, it will cost you less than 50 cents per refill!
I'm assuming that refilling other disposable cartridges would be a similar process, but if you know of a brand specific set of instructions, please post a link to them below!

Related:

Simple water saving tips
Recycling by the numbers