Control Systems & PLC's

Water Filter

Reverse Osmosis Water Filters

The water that comes out of your faucet is perfect. If you don't use a filter your body is the filter. Which of these two sentences are more true? Both are partially true.

In many places, tap water does not taste good. In other places, tap water has tiny amounts of substances you would not want to drink - and over a lifetime might have an affect on you.

There are many kinds of potential problems in tap water. Even if your city provides good water, it has to travel a long way through old pipes on the way to your house.

I use a whole-house ten micron sediment filter to filter all water going into my house. I change all the filters every five months, and they are dirty and red-colored, because of the rust and dirt in the water. When you use a whole-house filter, shower heads and faucet screens don't clog. Whole-house filters are separate from drinking water filters.

All reverse osmosis water systems require both sediment and carbon pre-filters. All filters need to be changed. Plan on changing sediment and carbon filters every six months or sooner, and reverse osmosis membranes every 2-3 years.

It's best to buy a dissolved solids meter, and test your water every month to make sure the system is working right. Pure water will measure zero parts per million of dissolved solids. Tap water usually measures at least 210 parts per million.

Don't get a liquid chemical test set, get a $25-$50 portable battery-operated tester with a LCD readout. These cheap meters only show the total dissolved solids in water - they can't tell you what is in your water.

Water filter systems and replacement filters are available on Ebay and Amazon, and many other places - even retail stores.

The hardest parts of installing water filters are connecting to the supply side of the water into your house, connecting to a drain line for the waste water, and installing a clean water faucet onto your sink. The rest of a water filter installation is easy.

You may need a plumber, or to buy a system where they will install it for you. The best systems have clear plastic casings, so you can see how dirty the filters get. The best systems also use standard-sized replacement filters, so you don't have to buy tiny, expensive, and proprietary filters.

Reverse osmosis water filters require both a sediment and a carbon filter in front of them, to screen out the dirt and most of the junk, before the water enters the reverse osmosis filter.

A sediment filter blocks particles larger than (e.g.) five or ten microns. That's an improvement over tap water, but it does not help the taste, or filter out tiny or dissolved nasty stuff in the water. The next step is a carbon block filter.

Almost all carbon block filters are activated. Activation is a process where high pressure steam is passed through coal to purify it so that it becomes almost pure carbon. Carbon is the fourth most common element in the universe, and is needed for life. Carbon makes an excellent filter, especially when extruded into a solid block.

Activated carbon block filters strain water to trap much more particles than a sediment filter can. The carbon in activated carbon filters have a positive charge that attracts chemicals and impurities. As the water passes through the positively-charged carbon, the negatively-charged contaminants are attracted and bound to the carbon.

Activated carbon block filters strain out sediment, dirt, bacteria, algae, chlorine, some pesticides, asbestos, and much more. They filter sub-micron size particles, making quality water that tastes good.

The water passing through activated carbon blocks still has some particles, chlorine, nitrates, fluoride, and other dissolved junk. The next step for the best quality water is a reverse osmosis filter.

Reverse osmosis filters force water through 0.0001 micron-wide holes, through semi-permeable membranes. Long sheets of membranes are sandwiched together and rolled up around a hollow central tube in a spiral.

The reverse osmosis filter removes 99% of the remaining junk in the water. It takes almost everything out, even the calcium and magnesium in the water. Most often a small carbon filter is used after the reverse osmosis filter, to improve the taste and catch a bit more of that 1% of junk the reverse osmosis filter lets go though.

Even after sediment, carbon block, and reverse osmosis filters, water is still not perfect. Chloramines and metal ions, while reduced, may still be in the water. For this reason, some systems include a final deionizing (DI) filter.

DI filters are usually cartridges filled with plastic-like resin crystals that grab the remaining ions in the water. After the DI filter, the water is very pure.

Reverse osmosis water filters generate waste water, and they produce only a few drops of clean water per minute. For this reason, most reverse osmosis systems have a storage tank to accumulate water. All reverse osmosis systems have a drain line for waste water, that is "wasted". The waste water can be used for plants, dumped down the drain, etc.

Ultra-pure water can grow algae very easily. When you take chlorine and other nasty stuff out of water, tiny microbes and sunlight can combine to make a perfect environment to grow harmless algae.

The quality of water filtered this way is cleaner than even distilled water. Some people think pure water tastes flat. Some people add a tiny amount of sea salt to pure water. For me, no salt is needed, pure water tastes like water should.

The Internet has baseless scare stories about how ultra pure water is dangerous. Hogwash. If you inject pure water, it may hurt you. Drinking pure water does not hurt anyone unless they are fasting.

The instant that pure water hits your mouth it's no longer pure. Nothing is better for making coffee, cooking, and ice cubes, than using pure water.

My observations over 20 years show that pets, plants, and people really like it. When growing sprouts - with pure water, I found they grew twice as fast as with tap water.

The truth is that ultra-pure water is missing minerals. If you get calcium and magnesium in your diet, you are more than ok. Ultra pure water has no lead, copper, barium, or other garbage.

For me the trade-off is clear. What I want from water is water. As long as you get calcium and other minerals from food or supplements you should be fine. Also, too much copper is not good for you, so why get it in your water?

About the Author

Mark D. Shapiro
The FAQ at
http://www.JudgmentBuy.com
is updated often and is full of useful information for anyone involved with Judgments. We are not lawyers, and can give no legal advice.

How much water do Brita maxtra cartridges filter before they need replacing?

I can get a gallon of spring water from the supermarket for 90pence. Is it worth getting a water filter?

I used my filter for about two months before replacing it. It really depends on the amount of calcification in your water. If the magnesium is very visible on the surface of hot tea, you'll be using it about a month.
The other thing is the reduction of plastic waste from bottles.
In Northern England the water is very low in calcified deposits, so the water doesn't really need filtering, just allow the light chlorine aroma to disappear. In the places like the South East, the water is horribly calcified.

Make it yourself water filter