pH & ORP

UNDERSTANDING PH AND ORP

To understand ionizer performance testing, you should have a basic understanding of pH and ORP. We’ll look at exactly what pH and ORP is, how to measure it, and the crucial variables to these measurements (or performance).

About 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 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. Typical tap water in the US or Canada runs at between pH6.0 and pH7.25 although extremes exist.

Measuring

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 to do it 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.
  • 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")-- It 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 microclustering, antioxidant and hydrating effects.

ORP is a "potential" energy 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. It is measured with an ORP meter. These 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).

The ORP of most tap water in the USA is between +150 to +600mv and so is an oxidizing agent. High pH ionized water demonstrates a –ORP and so is a reducing agent or “antioxidant”.

Understanding the crucial variables in Performance

pH and ORP alteration are highly variable and depends primarily on three factors:
  1. The source water and its natural mineral content – water varies widely in this respect
  2. The voltage applied to the water during electrolysis
  3. The flow rate through the ionizer’s water cell

These variables 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 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.

To illustrate this whole principle, lets look at two very different tap waters and their effect on performance. Remember the crucial variable is the dissolved mineral content or TDS which creates the pathway for the ionization to occur. In Carlsbad, California the tap water tests at 385 - 501ppm of TDS. The tap water in Seattle, Washington tests at approximately 40 – 80ppm. You could test water from an ionizer in Carlsbad at a given setting and flow rate and you would get a certain result. You could test the exact same ionizer in Seattle without altering the setting or flow rate and you would get dramatically different results. Is it the ionizer? No. It is the water as the main variable in performance. There is much less “pathway” in Seattle’s water. Further, you could change the performance in Seattle by adjusting the voltage and/or the flow rate.

Comparing ORP

Lastly comparing ORP is a tricky business. Stating absolute values is impossible. The only salient way to compare ORP in ionizers is side-by-side, with the same source water. Further, 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 Click Here to read more. 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.