A Good Gravity Bag?

I don't use it, but this one is popular and cheap:
http://www.ula-equipment.com/amigo.htm

It's easy to hang a Platypus! I have a Platypus 2+ water bottle, and I just hammered two grommets through the bottom plastic corner — one on each side. You can buy grommets at REI ($2 for a bunch) — or to do it more elegantly, you can also buy a grommet kit that includes a cutter/setter ($9.75).

I use a Platypus Big Zip that came with a pair of grommets already installed at the top (at the zipper end) and the spigot at the bottom. Works great with its large opening to fill with unfiltered water. I keep a cord tied through the grommets ready for hanging, and have a short length of hose attached between the spigot and the Sawyer filter.

Attached another length of hose at the downstream end of the filter, and capped the end of that hose with a valve that opens and closes.

If there's a need to filter larger contaminants, have also inserted a small pre-filter in the section between the Big Zip and the Sawyer filter to avoid clogging the Sawyer.

Don't see the above model of Big Zip with grommets on the Platypus website anymore, so it may be out of production. Googled the Big Zip and did find the grommeted version of the Big Zip available for sale at this website in the UK:

http://www.facewest.co.uk/pp/platypus/bigzip.htm

JRS

I use an MSR Dromedary bag and a Seychelle inline filter. I just cut the hydration kit line and inserted the filter. The advantage of having a closed bag is that you can use it while hiking too.
Richard, what type of pre-filter do you use?

http://www.tothewoods.net/HomemadeGearWaterBag.html

I purchased something similar to the above link from Dancing Light gear when they were operational for like $8. I placed a coupler in the bottom that allows for the attachment of a water filter inside the bag (katadyn). I really like this set up because it takes up no room in the pack when I am not using it…whereas the platypus bags do not collapse quite as much. You could just as easily place an in line filter on the outside of the bag with the use of silicone tubing….it is very similar to the ULA Amigo, but you get a bigger water bag and can adapt to use a filter that might filter faster for a larger group. Also, if you already have the filter, creating one of these on your own is relatively cheap!

I just put a couple holes in the edges and it works great. I was concerned that it might cause a rip, but the platypus material is strong enough to handle a hole in each corner. Using grommets sounds even better.