What is the least expensive way to make distilled water?

Wal-Mart has it for less than a dollar per gallon. Making it your self just is not worth the effort or expense. Remember you have to buy the distilling set up and also pay for the heat to boil the water. Herb

It would be more expensive for you to make it then it would be to buy it. I recommend buying a good water filter and filter your water of the contaminates. A britta filtration system would be ideal and inexpensive. None the less if you want to distill water yourself you'll need to buy the equipment to do so. It's basically a steam pot with an attachment called a worm. As the water steams/evaporates inside the steam pot it will travel through the worm into a separate container and be distilled. Drewfuss appears to have a pretty good idea to DIY. The ice would appear to be unnecessary though, but unsure.

Making distilled water is easy! How much it costs is another matter. You need to boil water and then collect the vapor and recondense it. Here is one way. take a fair sized cooking pot and domed lid. now take a heavy coffee mug or something similar. put the mug in the center of the pot and put a couple inches of water in the pot, none in the mug. now put the lid on upside down so the dome is sinking into the pot and put ice into the lid. turn on the fire. what will happen is the water will boil and the steam will collect on the inverted lid. it will run down to the lowest point and drip into the mug. now you have a mug full of distilled water. You won't be buying distilled water, but will be buying electric or gas for the stove. And spending time emptying the mug every few minutes. and making ice. You could make a solar distiller too, but it would be much slower and would probably not make it as fast as the humidifier used it. Why don't you just use clean tap water in the humidifier? if may require more frequent cleaning, but shouldn't hurt it.

Not worth it to make your own. It costs about $2 a gallon versus the cost of equipment and time to produce it. Distilling is based on turning water into a vapor. The vapor is then collected and cooled. The collected vapor is the distilled water. The process has to be completed more than once to get as much impurities out as possible.

reverse osmosis. 3 Stage 36 Gallon Per Day Reverse Osmosis System > http://www.osmotics.co.uk/products/3-Stage-36-Gallon-Per-Day-Reverse-Osmosis-System.html < .

Boil water and condense it on some cold glass and drip it into a bottle or get a ion exchange column from the supermarket.

Filter paper, just getting it can be hard though i'm sure it will be for sale online. It may take a while but it's as cheap as... Paper. Good luck finding a piece the roght size though...

You know what distilled water is, so work it out. Probably cheaper to buy.