How To Make Pure Water

Dirty Water to Pure Water
Working in areas of low TDS? You can probably get away with just a DI resin system for filtering!

Different areas have different levels of TDS (Total Dissolved Solids) present in the water.  This level of TDS determines how much you need to filter the water to use it for cleaning windows.  Many areas of Michigan, for example, have very low TDS (around 125 Parts Per Million), and many of our window cleaners can therefore get away with a smaller, simpler system.

What kind of system do you need?  Use a TDS meter on the tap water to find out.

  • TDS of 150 PPM or less = DI resin only
  • TDS of more than 150 PPM = Multi-stage system (Carbon filter –> RO filter –> DI Resin)

The simplest Pure Water filtering system consists of just a DI resin canister/tank that water is run through from the tap to the tank to the waterpole.  This single stage filtering system can make Pure Water of most tap water, but when working with tap water of a TDS of more than 100, this system can become very costly and less time-efficient as the DI resin will be used up much more quickly.

To lengthen the life of the DI resin, the addition of RO filters and carbon filters can aid the process.

What are all these filters and what do they do?

Carbon Filter

Activated carbon
Activated carbon – per Wikipedia

In a multi-stage system, the Carbon filter comes first.  It consists of charged carbon and absorbs impurities to help the other filters do their job.  Think of this as a large sieve that captures larger particles.

RO Filter

A reverse osmosis filter
A reverse osmosis filter – per Wikipedia

This is the second stage of a multi-stage system.  The Reverse Osmosis filter uses a semipermeable membrane to further purify the water.  It traps a large concentration of impurities.

DI Resin

DI Resin
DI Resin

The final stage in a multi-stage system, the Deionization or Ion-exchange Resin consists of charged resin beads that “polish” the water and complete the process of making it into Pure Water.  With a multi-stage system, about 80-90% of the impurities have been removed before they reach the DI resin.

Do you have additional questions about Pure Water filtering and the products available?  Comment below or email us from the About Page!

Or… Shop for Pure Water systems now!

Ettore 3-stage EZ-Pure System
Ettore 3-stage EZ-Pure System.

2 Comments



  1. All types of filters are essential to get safe and pure water. It removes the bacteria, viruses, and infections present in water.

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