Hmm BRITISHBerkefeld...Ok so they arent German. TY Daman, wife swore it was Birkefeild.
Most of the personal water filters Ive seen are good for less than a gallon a minute. We had 22-24 people in camp, quite a few more some days. Someones arm would have fallen off. Think Bubba's gonna need of those big old things.
My experience with the foam prefilters found on the PUR models is they suck. Extrapolating they all suck. I still cover my "prefilter" with a coffee filter and rubber band it. Actually use those hair things as they stand up better.
Im in the woods in Eastern US or Canada so it seems im either getting water from a spigot (good) or pulling it out of slightly turbid bodies (not so good). Havnt had to resort to really turbid (bad) or stagnant (ugh) yet, so I cant comment on tough stuff. I have seen folks clog their filters in water that didnt look that bad. (Then again who knows how "used" those filters were.)
Get as much of the muck out of the water before you filter. Increases filter life and limits clogging. Problem is if you are filtering nasty water you probably REALLY need it. Great time to find out the limits of your gear.
Ive seen it published that the chances of any type of trouble from drinking unpurified water in North America is extremely slim. Im with DRjarhead, et al. So if your in trouble, and need water, drink, purified or not.
But nothing worse than shitting yourself for miles as your hoping the Imodium kicks in. Bad enough at home- well think about finite toilet paper and having to walk 10-15 miles a day. I dont want beaver fever or worse, parasitic infections. no worms plz. Heard horror stories while in Africa, 'course the gents may have been overstating things for effect - but I dont want worms. So I purify.
This has taken a decidely backpacker-ish slant. But I guess thats when we all have experience without tap water.
Bubba, do you have a well? If so what about a hand pump? We have a farm that has a hand pump, use it when Im there to wash up the dogs, my boots, no outside hose bib. Not sure how its connected to the well but think it would sure beat the pond.
Luck
Alac