First Need Water Filters

 

First Need water filters provide a level of safety and quality that I trust. I use them and have them in my emergency gear.

There are several models to choose from:

First Need Portable Water Purifier 

I like this one for it's ease of use and versatility. The fact that it can do gravity feed is a big plus in my mind for emergency preparedness. This lets you filter water without pumping (but it takes more time which backpackers usually don't have.)

From the Amazon website:

The most effective portable at any price. Effective against cryptosporidia, bacteria and viruses; unmatched in removing harmful chemicals. "Direct Connect" to Nalgene bottles, sanitary cover to protect outlet, longer tubing, rugged, comfortable handle, greater capacity and fastest flow of all. Self-cleaning prefilter and gravity assist system included. No iodine needed!

 Flow rate of 1.8 qt/minute.  Average canister capacity of 125 gallons.

First Need XL Portable Water Purifier

This is essentially the same as the one above but with a larger filter and capacity.

Kills or removes bacteria, viruses, giardia, cryotosporidia, parasitic cysts, pesticides, algae, odors, colors, sediment, foul tastes, herbicides & organics. Purifies water in one pass without using chemicals. Flow rate of 2.0 qt./minute. Average canister capacity of 150 gallons. Pre-filter eliminates the need for backflushing. Integrated, adjustable float. Tote bag and "hands-free" gravity feed kit included.

 

And for Home, Boat, or RV use, you might want to consider the General Ecology (maker of First Need) Seagull Mark IV.  See the links section for General Ecology's website.