They suck for getting water out of rocks, but for desalinating sea water they work great. Salt isn't very volatile. <img src="/images/graemlins/wink.gif" alt="" /> I built mine for under $25, it has no moving parts, and can be repaired with duct tape.

-Mark

got pictures?

Here is my current setup:


The tub is a 16-gallon pre-formed water pond container from Home Depot ($16), the plastic sheet on top is just some clear vinyl from Walmart ($6), hanging inside to collect the purified water is a funnel from Walmart ($1.98) with tubing attached ($0.99). the tubing comes out the side of the container and is currently plugged with a golf tee.

The water puddled on top is from a recent rain. I've found it doesn't affect the production rate any so I left it there. On a cloudy, cool day it'll only produce 125mL of water. On a sunny, hot day it'll pump out a quart or more. Luckily here in Houston we have plenty of sunny, hot days! Individually this may not seem like much, but several together can produce enough water to get by. The raw materials are cheap and have many uses around the home, so it's not wasted money. When needed, I could have eight ready to go in under an hour. It does work better when set directly on the concrete patio as the absorbed heat keeps it running long into the night, but draining it was harder so i stuck it up on the table as shown.

I have tested it with salt water and it worked fine. There are no metal parts to corrode. I prefer to use water from my three 55-gallon plastic pickle drums that collect rain water. There are also several ponds (and swimming pools) within easy water-hualing range. Raw water sources are not a problem. I just dump 8-10 gallons in the solar-still, seal the vinyl top with bungie cords and forget about it until the next morning.

-Mark

Yeah, I've seen some stills like that but more permanent, basically a wooden frame lined with black RTV covered with a big sheet of glass like a shower door. Those can make up to a gallon a day. An RO desalinator is still a lot more attractive: portable, much faster, and doesn't depend on sunlight.

Nicely done Blast. <img src="/images/graemlins/cool.gif" alt="" />

Is the funnel both the collection and the storage vessel for the fresh water? Is the tube connected directly to the funnel? If so, how do you keep the funnel in an upright position?

Or is the funnel sitting in something like a quart jar with the tube inserted in the jar?

The funnel is used for both collection and storage. This funnel is about ten inches across and holds quite a bit of water. I attached the plastic tubing to the bottom of the funnel with silicone glue then ran the tube out the side of the tub through a hole (also sealed with silicone glue). The tube is left raised higher than the funnel to prevent siphoning until I'm ready to drain it. When I want water I yank out the golf tee from the end of the tube and drain the water into a bottle.

The funnel hangs inside the tub by three strings. I can adjust the strings from outside the tub to align the funnel after placement of the vinyl sheet.

I tried smaller funnels in earlier versions but as the water droplets joined up and ran down the plastic often they'd get heavy enough to drop before reaching the center point. Using the larger funnel allowed me to collect water from a larger zone.

This wouldn't work well in a bugout situation, but if you are hunkered down they are great. You can make them out of any container or even a hole in the ground lined with plastic. It's cheap, easy, and incredibly low-tech.

-Mark

Assuming you have a source of water how would you make it potable? If you have propane you might not want to use it to boil water to make it potable. You might want to conserve it for cooking.

How about something like Polar Pure?

you mean this one: http://www.cawst.org/technology/watertreatment/filtration-biosand.php

some other stuff:
http://ceemeng.mit.edu/~water/ceramic_tech.htm
http://almashriq.hiof.no/lebanon/600/610/614/solar-water/unesco/35-46.html

i really don't understand why so many people rely one the MSR Miox, it need batteries and salt to work. The testing strips are expensive. Aqua Mira is almost the same stuff in liquid from, but doesn't need batteries.

Sorry I've been gone so long.

PaulR is correct: "25 or .5 gal/day is bare survival, i.e. avoid death by dehydration. If preparing, go for 1 gal/day or more."

And that is in a temperate climate with very LIMITED activity.

August in the most of the US with any activity involved, 1 gal a day won't be enough.

Nothing in your body works correctly without water.

Dehydration is also underrated in the winter, since people seem to feel less need to drink.

Feeling "thirsty" is not a good way to judge hydration, either. Other than keeping urine clear with enough water intake, pinching the skin on the back of the hand and seeing how fast it returns (less than a second) will also give you an indicator.

Chapped lips are also a sign of dehydration, along with cramps, headaches, etc.

I recommend a read of Cody Lundin's bok 98 point six - he really covers it well.

I can remember humping (ok, route marching) in the Asian jungles. Juice and water with breakfast, 4 quarts before lunch. Refill at lunch. 4 Quarts by dinner. Head on in. Drink tea, water, etc until about 8 pm - Urinate the second time for the day...

Anythine with caffene is a NEGATIVE not a positive. <img src="/images/graemlins/smile.gif" alt="" />

Filters are not reliabe for heavy metals, solvents, etc.

Solar stills ... Not. Now putting a bag around vegetation can often work.

Distillaton (with proper equipment andprocedures) is probably the most safe and reliable method of purification.

Chlorine is great for "bio" decontamination, HOWEVER, chlorine bleach needs to be fresh - it has a fairly short shelf life, believe it or not. (IIRC it turns into ...salt water..."

Some cysts and spores are just darned hard to kill.