sand filter

SLOW SAND FILTERS
Remember a few weeks ago when I told you about the sale at Amazon on the book “Peak Oil Survival”? $2.99 and a heck of a deal. Did you get your copy? Chock full of nifty items of expedient and improvised methods of water purification, heating, cooking, etc. Even at full price of $12.95 ( most likely around $10 at Amazon ) it is a great resource. Web sites abound that teach the same thing but this is all condensed and presented in paper form. Just what you want after GridCrash. Most likely you didn’t get your copy. To get free postage you have to buy $25 worth of books from them and with postage of $3.50 the book is less of a bargain. So you put off buying it. Okay. Do not fear.
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I will be shamelessly using it to research articles and giving you the information. Then you take your 70 page notebook you got at Wal-Mart’s back to school sale for a whole ten cents and carefully sharpen your pencil stub with your Boy Scout knife ( is it me or is it just crazy that a manual rotary pencil sharpener is more expensive than a battery powered one? ) and write down the pertinent details so you won’t forget when the power goes down. Or you can spend fifty cents printing out each of my articles ( printer cost factored in with ink cost as well as paper ) which really is just plain silly since I usually take a three sentence idea and turn it into a page and a half of rambling which makes perfect sense for electronic newsletters as it provides entertainment value but almost no sense when it comes to killing trees to present an idea. It is cheaper just to buy this darn book. Peak Oil Survival by Aric McBay.
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Today’s topic is the slow sand filter. You can find the information online, where McBay got his information.
www.refugeecamp.org/learnmore/water/slow_sand_filter.htm
You need a container full of sand. The container should have at least 26 inches of sand in it. Use a mesh screen to get a uniform size. Take your suitably tall container and make a hole at the bottom of the container. Get a perforated drainpipe ( perforated part in the barrel only ) with the end going in the barrel plugged. Around the pipe place small stones and seal the pipe exit in the barrel, with caulking or preferably marine epoxy. Now put your sand in the barrel. A flat stone on the top of the sand will allow the water to be poured in without disrupting the sand. Also, the stone is needed to allow the top of the sand to grow a beneficial microbe.
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This type of filter works because of a biological microbe named schmutzdecke. It grows on top of the sand and its job is to eat organisms in the water. It can take up to two weeks to form so any water before that is not fit to drink. Also, to keep ol’ Schmutzy alive you need to keep the water level above the sand at all times. For this reason it makes sense to have a flow control on your drain pipe. Then at night sleeping you don’t have to worry about the water draining away and killing your little friend. If you don’t have a spigot, attach a flexible hose on the drainpipe and raise the hose above the top of the water level to stop its flow.
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You should have that hose anyway, since you will need to initially fill the barrel from the bottom up. The feed water is placed at a higher level than your filter barrel and fed into the drain pipe. This allows the sand to remain free of air bubbles that slow the flow of the water. Also, when the schmutzdecke layer gets too thick you will see a severe slow down in the water flow. To clean drain the level of water down to just below the top of the sand and scrape off the layer of scum. Refill from the bottom. Now wait another two weeks for the microbe to form again. A pain in the butt? Sure. But a long lasting filter. Usable over and over again. Not subject to the need to buy a replacement filter from England. And a good producer, about four to eight inches of water an hour if the flow is not hindered. If you used a thirty gallon plastic barrel you would see several gallons of water an hour. Have several so there is no disruption in water output during the microbe re-growth period. *
I like solar distillation units myself, and it makes sense out here in the desert. But it is helpful to know about alternate methods such as the slow sand filter. The more choices we have for every necessity, the better our chances for survival. Having a lone factory made filter for all your water needs is a recipe for disaster. Having just one gun, no matter that it is the neatest, fanciest, prettiest Mattel Plastic Gun is a recipe for disaster. Or all your gear in one spot. Etcetera. Diversify. Learn new tricks even if you are an old dog.
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A note on my earlier article on tooth care. If finding a source for silver wire is an impossibility and you want a more permanent source of equipment to get food out of your teeth than wooden toothpicks, Wal-Mart has a dental kit in the toothpaste section that contains a dental pick. Under five bucks.
No more guest articles to post on Sunday, so you are on your own tomorrow. So this is your last chance before Monday to buy my books!!!! www.bisonpress.com