The Spot Free Water Filter Myth

Spot Free Water Filters. We have seen them come and we have seen them go. The great sounding commercial or website promising you cheap and easy production of spot free water. They show you washing the car, the boat and even the windows of your house. Spot Free, yes. Economical, no. They leave that part out and and when you figure out how short the expensive filter lasts, you never buy it again. This article will tell you the whole truth. 

Making spot free water can be very economical only if you do it the right way.  

Spot free water filters contain deionization filter media. A deionizer is basically a chemical magnet that trades spot causing minerals with Hydrogen (H+) and Hydroxyl (OH-). The capacity of the filter is based on the number of exchange sites in a given quantity of media. Once the exchange sites have traded the stored H and OH, the filter begins passing spotting minerals in the rinse water.

A Water Softener is also a deionizer but Instead of trading spotting minerals for H and OH if trades only Calcium (Ca++) and Mangnesium (Mg ++) for sodium for Sodium (Na+). This makes the water mostly sodium chloride which not only will leave many spots, but the chloride will corrode metal sufaces. 

Spot free deionizer filters contain two types of deionizer media. There is Cation (cat-eye-on) and Anion (an-eye-on).

 There are two configurations used in these filters.

The Mixed Bed configuration is a removes 100% of the dissolved minerals and is the most common configuration of a deionizer filter.  

A Mixed Bed Deionizer used 60% cation media and 40% Anion media that is blended giving it a chemcial equal amount of exchange sites and therefore better removal of the dissolved minerals.

The Separate Bed configuration is a removes about 90% or so of the dissolved minerals but lasts longer since it does not trade as many site. 

A Separate Bed Deionizer filter uses a 50% cation and 50% anion media that is not blended but instead kept separate. These dionizers allow minerals to pass through giving a long life in terms of gallons of throughput water while containing a higher level of mineral contaminents. 

How long will a spot free water filter last?

How long a filter will last all comes down to the math. There is no black magic to it. 

Article in progress.... More coming soon.