The Kalalau trail is very appealing but also very difficult, even for experienced backpackers (backpacking = hiking for several days and carrying everything you need). It can be harder than trails of similar length and elevation gain in the mountains, even without the altitude factor. The main difficulties are: steep sections of trail, muddy areas, narrow trail above cliffs, overgrown trail, rocky and uneven trail, heat and humidity, carrying supplies for 4 days-3 nights minimum (and you’ll wish you could stay longer).

I don’t want to discourage you, but this is not a good trail to learn backpacking. To be safe, I really suggest you do at least 2 moderate overnight hikes near where you live before going to Kaua’i. There is a lot of knowledge you need: planning food, planning your camps, packing your gear, etc. And of course, you need the equipment: large backpack, lightweight tent, sleeping mattress, water filter, etc. Then you can see how well prepared you are for the added difficulties above.

Any bookstore should have a book about backpacking, something where you can learn about equipment and planning. For details about the Kalalau trail, there is On the Na Pali Coast by Kathy Vallier and the NW Kaua’i Recreation Map (it has a lot of text on the back). You can see them in another article (http://great-hikes.com/blog/kalalau-trip-reports/#books) and both are available from Amazon through my “bookstore:” http://great-hikes.com/blog/bookstore

I’ve always used the cheapest 1 micron filter I found on the market. They’ve worked well and I’ve never gotten sick from anything. Here are the links:

• MSR SweetWater Purifier System includes the drops. You can also buy the MSR Sweet Water Purifier Solution separately, but one bottle (2-Ounces 59mL) is enough for hundreds of quarts. It is relatively easy to pump, goes a little faster because it pumps on both strokes, you can clean the filter for a longer life, and you can replace the filter for half the cost of the whole thing (mine died after several years and 2 filter replacements).
• Katadyn Hiker Microfilter (they also have a slightly improved PRO version now) and then I just used the SweetWater drops above, because they don’t have their own. Although I see they have a new filter that does 0.3 micron, which theoretically will eliminate any leptospirosis bacteria. This one is a little harder and slower to pump (only on the downstroke), but a simpler and more rugged design. You can change the filter as well, but I haven’t done that yet (though I probably should by now).

You should also be able to purchase these at any outdoor store such as REI. That might be recommended so you can look at the products and even try them out (REI usually has demonstration models sitting out). These two models might be a bit small for 4 people, but then again, you want the lightest filter possible–you’ll just have to spend a bit more time pumping every time to fill up everyone’s bottle.

I don’t know how the UV or ozone purifiers work. They’re usually smaller and lighter, but they probably require batteries, which might be a limiting factor.

Yes, there is enough water along the way, unless you drink more than 1L per mile–I sweat a lot, and even I get by with a 1.5L bottle. The places to find flowing water are Hanakapiai Valley (2miles from trailhead), Hanakoa (4 miles from previous), and almost every mile thereafter. Oddly, the 2 “wet” valleys between Hanakapiai and Hanakoa have little surface water, while every little valley on the “dry” part after Hanakoa has a good stream. Of course, weather patterns can change, but I think unless there is an extended drought, Hanakapiai and Hanakoa will always be flowing.

So the longest stretch without water is always 4 miles, and often much less.

I know you say you do have a “filtration system,” but just to be clear for everyone, filtration is technically not sufficient. Leptospirois is a long bacteria, but only 1 micron in diameter, so theoretically it could go through a 1 micron filter (still the smallest on the market I believe). For this reason, I also add purification drops to my water after filtering, I use the brand SweetWater. Perhaps the new UV or ozone filtration systems don’t need this, I haven’t read their specifications yet.

Here’s a hiking secret of mine: try to hike at a pace where you can breathe through your nose–and avoid talking. Breathing through your mouth loses more moisture and can contribute to dehydration. That’s how that old trick of sucking on a stone reduces your water need.

Are there enough water sources available to travel with 3L of water and my filteration system for two?

Sincerely,

Yar