I haven't tried a Sawyer filter with a newer Platy, because my Platys date from before the thread configuration was changed. I switched to Evernew bottles five years ago because I was sick and tired of losing caps from the Platys and having to pack extra caps. Evernew bottles have the caps attached with a toggle, solving the lost cap issue. Maybe I'm just prone to losing bottle caps, but I seemed to lose one or two on every trip!

I have read that replacing the Sawyer washer with a standard hose washer from the hardware store solves the Platy leaking problem with a Sawyer filter, since the hose washer is slightly thicker. However, I have no idea if this is true--has anyone tried it?