Water filtration

I had a few questions about water filtration lately so I thought I would give a basic breakdown of different types of filtration.

Some types of water filtration media strain out particles.  The amount of filtration depends upon the micron rating of the filter media.  The smaller the number the smaller the particles it will filter out.  These types of filters are generally referred to as sediment filters since they filter out actual undissolved particles.  Another type of filtration is actually a process that changes the chemical make up of things which are dissolved in the water.  An example of this is when you filter water that has chlorine content through activated carbon the give and take of electrons as the water passes through the carbon filter media changes the chlorine into harmless chloride.

Most dual or multi stage basic filter systems use a sediment filter followed by an activated carbon filter.  Most whole house water filters use a process of layering filter media in a single tank to filter many things out all at once.  Single, dual, & multi stage systems can be installed under your sink to improve the waters taste and odor at a faucet, can be installed in line on a refrigerator, and can be installed as a whole house system at the water service entrance to the house to filter everything.

Reverse osmosis water filtration

 Reverse osmosis uses a combination of different stages to filter your water.  A basic RO system will have a carbon pre-filter followed by a membrane filter (the actual reverse osmosis stage) and then a carbon post filter.  The actual reverse osmosis stage filters water that has dissolved impurities in it.  This stage actually works much like a sediment filter except that the way this system is designed it allows water with dissolved solids to pass through to a drain and the “pure” water is allowed to pass through to a storage tank.  Normally we see these types of units installed under a kitchen sink with a separate spout mounted on the sink or counter top.  This is the most effective way of getting purified water.  

Though purified water may not necessarily be the best thing for you… water with useful minerals is actually better in most cases.  Reverse osmosis does waste a lot of water, but it is very effective.  There are also very large reverse osmosis systems available.  It is possible to have reverse osmosis water for your whole house, but it would be quite a costly system, starting at about $5,000.00 just for a small whole house reverse osmosis filter system.  

Installing these types of systems requires that you have special piping in your home and you will want to separate the toilets, sprinklers, hose bibbs, and possibly some other water outlets onto unfiltered water to conserve the filtered water.  I wouldn’t recommend this for anyone, but I thought it was interesting to know that these types of systems are actually available.

Water Softening

Lastly, there is water softening, which is a whole subject in itself.  Living in southern California we nearly all have hard water.  It leaves crusty deposits on our faucets, shower heads, and other plumbing fixtures.  Hard water leaves your skin dry and makes it so that you need to use more soap to clean laundry than you would if you had soft water.  Hard water also builds up in your water heater.  If you have a tankless water heater unit it probably has a warranty stipulation that requires you to have some sort of scale inhibitor to keep the hard water build up from getting into the heat exchanger.  If you have a traditional tanked water heater you likely hear a rumbling sound when it is heating due to hard water build up in the bottom of the tank.  There are many approaches to dealing with hard water, but the only way to eliminate hard water completely is to “soften” the water.  

A traditional water softener uses a process called ionic exchange to remove the hard water ions (typically calcium and magnesium) which are in the water and replace them with either a sodium ion or a potassium ion (I recommend using potassium).  Some scale reduction filters use this same principal but just do less softening.  Other types of scale inhibitors include pass through filters and electronic units that claim to isolate the hard water molecules in some manner in order to allow them to pass through your plumbing system without attaching to anything.  

I’ve personally found that most of these types of system are only marginally effective.  A water softener requires it to be connected to the inlet water supply to your house, must be connected to a plumbing drain, and needs an electrical connection.

As a side note, most municipally supplied water is tested regularly and must pass certain safety regulations set by the government to make sure it is safe to drink.

If you have more questions about water filtration call Mitch today at (562) 242-3218

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