I was reading a post the other day about various methods of fluid intake while cave diving. Everything from Capri Suns to underwater fluid bags was mentioned. However, one thing I did not see mentioned got me to thinking. Does anyone know the water quality for most caves? Would just removing your reg and taking a sip be advisable? I know that I have had it preached to me from a very early age that even the most picturesque mountain stream contains a number of digestive tract unfriendly organisms and bacteria but would the natural filtration through substrate make the cave waters more agreeable?