The Water Classroom

What is pH?

by Ed R Published 10.20.2012

What a funny word, pH. Actually, it’s not a word at all but an abbreviation. Most of us kind of know what it is. We learned about it in school, and then quickly forgot. But, if you have a fish tank or a garden you know that it is important and something that you have to pay attention to.

pH is essentially a measure of the relative acidity or basicity (alkalinity) of a solution or soil. Some things like tomatoes favor a slightly acidic soil, some plants don’t, which is why lime (calcium hydroxide) is added to “sweeten” the soil.

pH is measured on a scale of 0 to 14. A pH of 0 is extremely acidic and a pH of 14 is extremely basic. If something is acidic that means that it has a lot of Hydrogen (H+) ions associated with it. If it’s basic (alkaline) it has Hydroxyl (OH-) ions in a greater amount. A pH of 7 is neutral which means, that the H+ ions and OH- ions are in equilibrium. So, when they are in equal amounts, guess what you get? H+ + OH- = H2O. The pH of tomato juice is 4, Milk of Magnesia is 10 and blood is generally about 7.4. According to the EPA, the Secondary Maximum Contaminant Level (SMCL) for water should range between 6.5 – 8.5.

The pH scale is logarithmic which means that each point on the scale equals a ten-fold difference. As an example, a solution with a pH of 6 is 10 times more acidic than a pH of 7, and a pH of 5 is 100 times more acidic. Most organisms, including us, prefer to have a neutral (7 or so) pH in our bodies and in our environment. Acid rain has been responsible for killing many creatures. Frogs and fish are especially susceptible to changes in pH.

It is relatively easy to measure pH; there are many kits available to test water or soil. It all depends on how accurate you want to be. Simple test strips, chemical color indicators and meters are often used. Meters are usually the best. Now that you have some background on what pH is, you might ask yourself why it is called pH. (Ha! Ha! Made you sit through the Chemistry and Math first!)

The generally accepted reason for the term and abbreviation pH has to do with the first person to describe it. In one of his papers, S.P.L. Sørenson made a reference to the “hydrogen ion exponent” and gave it the designation PH, or pouvoir hydrogene or the “power of hydrogen” (as in concentration). In 1920, W.M. Clark, as a matter of printing convenience (printing was done by the hand set type process, letter by letter and subscripts and superscripts posed difficulties), decided to adopt pH in place of PH.pH Chart

So, how can pH affect water? If you have low pH or acidic water it can corrode your plumbing and impart metals like lead into your drinking water. Blue-green staining from copper corrosion can be an indicator that the pH in the water is too low. The fix is relatively easy; all you need is a neutralizer. This is basically a tank with a special media inside, usually Calcite (Calcium Carbonate). The neutralizer technology is fairly simple and doesn’t require a lot of maintenance. For the most part, you’ll just need to add some more calcite when it gets low. The best thing to do if you suspect you have water problems due to pH levels is to consult your local water treatment professional.

Contact Ed R.


Fluoride: It's not just in toothpaste

by Ed R Published 6.15.2012

When we think about fluoride we immediately associate it with dental products, “Oh yeah, that’s the stuff they put in toothpaste isn’t it?” While true, this is not the only source of the substance. Most natural drinking water and nearly all food have trace levels of fluoride in them. What’s more, in the U.S. approximately 50% of our population drinks water that has had fluoride intentionally added to it. The reason: proponents of fluoridation and the ADA (The American Dental Association) specifically, have shown that fluoride, when ingested or added to dental products in the right amount, reduces the incident of tooth decay. Notice that I said in the right amount. I’m not going to get into the debate of whether fluoridation is good or bad. Like many things in life, a little of something may be good, and a lot may be bad. Nuff said.

This whole subject has been controversial for more than 60 years. For an in-depth report on this subject I refer you to the August 1st 1988 C&E News Special Report “Fluoridation of Water” written by Bette Hileman. You may find the report through a web search or at your local library. While a little old, it contains a lot of very good information, both pro and con.

Fast forward to 2012. It seems that this topic is now coming back around. What we thought were proper levels back then, are now being re-assessed and it is generally believed the acceptable or beneficial amount of fluoride in drinking water should be lowered. Well, that’s not much of a problem for cities or towns that intentionally add it to their water; they will simply dial back the dose. But what about the estimated 15% of our population (43 million people) that get their water from private wells? How do they know if they have a safe level of fluoride?

Well, the answer lies with the agency in your particular state that is responsible for your drinking water. This is a great resource to find out about “What’s in your Water.” I didn’t say “wallet”, but it could be if your level is too high and you need to do something about it. An excellent example of the type of information that is available can be found at: www.epa.ohio.gov/ddagw/gwqcp pubs.aspx. You can just click on the fact sheet for the short version (about three pages) or the full report (10 pages). Your state may have a similar site. Or, if you are really concerned, have your water tested by an accredited lab, that way you will know exactly where you stand.

 

Contact Ed R.