What prefilter do you use with your chlorine drops?

it would help to know what bottle you intend to use.
on a standard 26mm bottle lid, you can cut out a hole in the cap and insert a small disk of mesh screen, from a kitchen faucet or cut from a coffee filter basket.
I use a bandana so I dont have to keep track of an extra lid. bandana serves multi-purpose, filter/lid does not.

If you use platy bottles the pre-filter cap works very well and weighs next to nothing. I made one of these using coffee filter mesh, and fill my bottles by using my pot.
This might help
http://www.freewebs.com/jasonklass/waterbottlefilter.htm

Phil

I use a coffee filter as well

Here's the Platy filter cap with gold coffee filter screen that I showed on here a couple of years ago. I still use it now that I've switched to tablet form.

Coffee filter as well, it cut them to resize it smaller.

John, I don't drink coffee (Never had) nor have I ever made it- were can I get a coffee filter and how much can I expect to pay for it?

Tad… This was a spare, and slightly damaged one I'd had for awhile. One filter would make at least a half dozen caps… if one had a use for that many. They seem to run about $11 at most most stores, but you might try thrift shops first.

The coffee filter looks like a good idea, I might try to make one that will fit on top of a wide mouth nalgene cantene so I can filter while its filling in the bottle.

I found something called a paint strainer at the hardware store. It's just mesh fabric much like bug netting on a tent. I'm going to give it a try. I haven't tried it yet. Cost $2 for a couple of these pieces of fabric made to go over a 1 gallon can of paint. I figure I can cut a square and use a rubber band.

What about cheese cloth from the fabric store?

I've got an order coming from filtersource.com. Its a polyester bag filter with an absolute rating of .5 microns. I'm gonna rig something up with half a soda bottle and rubber bands. The only thing i'm concerned with is flow rate. I have a feeling its going to be too slow to use "on the go" as opposed to an in-camp gravity filter. I'll try to post when I've got some results, with a description of what I made. Filtersource.com was really great to deal with–very helpful customer service.

http://www.filtersource.com/store/listCategoriesAndProducts.asp?idCategory=117

UPDATE: the filter material was too thick and would not let water pass through at any sort of reasonable rate. Its a no-go. I'll chalk it up to a learning experience

I think I stole this idea from John Haley, but I used 3 layers of NoSeem netting bonded in place with silicone.

It is very effective.