Water Ionizers: Water pH and ORP

What is pH?

pH stands for "potential hydrogen”. It measures alkalinity or acidity on the pH scale that runs from pH0 to pH14. A pH7 is neutral which means it is neither alkaline nor acidic. Values below pH7 neutral are said to be acidic and values above pH7 are alkaline.

The pH scale is logarithmic (like the Richter Scale), meaning each full point increases or decreases by a factor of x10 rather than a single unit. For example a pH8 is ten times more alkaline than pH7, and a pH9 would be 10x10, or one hundred times more alkaline than neutral. Typically, tap water in the US or Canada runs at between pH6.0 and pH7.25 although extremes exist.

Measuring pH

Measuring pH is relatively common practice. For example, the pH levels are routinely monitored in swimming pools, fish tank maintenance and maritime applications. The equipment for measuring pH is fairly accurate and readily available.

pH Reagent Drops are typically a reddish color and when dropped into a clear liquid, turn the liquid the color of the corresponding level of pH on the pH Color Chart. They are very accurate but rely on color interpretation. If stored properly, drops do not lose accuracy and never need calibrating.

pH strips that test urine are also popular for testing body pH.

Electronic pH Meters use a digital display and indicate a numeric pH value. People incorrectly think these are more accurate since they read to two decimal points. A strong word of caution: any electronic meter must be regularly cleaned and calibrated. If this is not done properly, then you end up with an incorrect measurement displayed to two decimal places! Meters range from inexpensive handheld portables ($50 to $250), to very expensive bench top models ($600 to $2000+) that would be considered Laboratory Grade.

About ORP

The other way an ionizer alters the water is to turn it into a powerful antioxidant, measured as ORP ("Oxidation Reduction Potential") ORP is a more complex concept and is an extremely difficult measure accurately. ORP is sometimes referred to as "Redox". An ionizer's alteration of the ORP of your drinking water is what causes the micro-clustering, antioxidant and hydrating effects of ionized water.

ORP is a "potential" power that is stored and ready to be put to work. An analogous way to look at ORP would be to consider pressure. When you blow up a balloon you use energy that creates force. As long as the balloon remains closed, this force is a “stored potential energy” in this case measured as air pressure. When released, this “potential” energy becomes kinetic energy.

Potential electrical energy in liquid can be measured with an ORP meter. ORP meters display extremely slight, and highly variable differences in the electrical properties of water. ORP readings are expressed in millivolts (1/1000 of a single volt). ORP meters range in price from $100 for a handheld “tester” to over $3,000 for more sophisticated laboratory equipment. Regular cleaning and calibrating with proper solutions is even more crucial than with pH meters to achieve accurate and consistent readings.

ORP measures the presence of oxidizing or [oxidation] reducing agents by their specific electrical charge, thus Oxidation Reduction "Potential". Oxidation in simple terms is what turns an apple brown after it is cut or causes metal to rust. Rust weakens metal and signifies the deterioration of the apple. High pH water has more "reducing" agents (-ORP) and low pH water has more oxidizing agents (+ORP).

Understanding the crucial variables in Performance

pH and ORP alteration are highly variable and depends primarily on three factors:

• The source water and its natural mineral content – water varies widely in this respect
• The voltage applied to the water during electrolysis
• The flow rate through the ionizer’s water cell

Mineral content, voltage and flow rate have a dramatic effect on pH and ORP

Mineral Content: An ionizer works primarily on the mineral content in the water. It is the dissolved mineral content (referred to as TDS) which creates the pathway for the “ionization” (or more correctly electrolysis) to occur. Water without mineral content or TDS, like reverse osmosis or distilled water, will not conduct the current and therefore can not be “ionized”. This first variable is the most crucial to performance. Tap waters vary widely in the dissolved mineral content. The higher the mineral content (typically “harder” water) the higher the levels of pH and ORP alteration an ionizer can achieve; the lower the mineral content (typically “softer water”) the lower levels of pH and ORP alteration. The importance of this variable can not be emphasized enough.

Voltage: The heart of an ionizer is the water cell which contains the electrodes. The electrodes are what deliver the current and creates the “ionization”. We control the voltage conducted through the electrodes and then to the water by selecting the different "Alkaline" settings on an ionizer. The higher the Alkaline setting (or voltage), the more alteration you will achieve in pH and ORP.

Flow rate: The flow rate through the machine determines how long the water is actually in contact with the electrodes receiving the voltage and the effects of electrolysis. If your flow is fast (say you could fill a quart or liter in 15 seconds) then the water is not processing very long and not receiving much alteration. Conversely, with a slow the flow rate (say the same quart or liter took 60 seconds) the water is in the chamber in contact with the electrodes longer and will receive more alteration. You can always achieve higher pH and ORP readings with reduced flow rates. Simply put, speed up flow rate, you get less performance; slow it down and you'll get more performance. So controlling the flow is an important variable.

Comparing ORP

Lastly comparing ORP is not easy. Stating absolute values is impossible. The only salient way to compare ORP in ionizers is side-by-side, with the same source water. Furthermore, pH and ORP are not tied to another. In other words you can measure ORP in two pH9 waters and get two very different readings. Another factor to consider when comparing ORP is the level of pH you will actually drink. Most people find water over about pH10 does not taste good. Given this fact, testing ORP at those levels is where the real bang for the buck is; ORP at a pH level you are going to actually drink. If you drink pH9 then the ORP you get at pH9 is the effective ORP in the ionizer. Not some “absolute” or even extraordinarily high ORP.

So understanding performance is like understanding a dance between the three variables. It is also important in understanding the need for truly scientific testing; these variables can be manipulated without you knowing it during testing. Understanding this dance is crucial to making an informed decision when purchasing an ionizer, and also in getting the most out of your ionizer’s performance.