pH Primer for Preppers, Part 3—Strips or Meters?

The first two articles in this series addressed some important reasons for being able to check the pH of foods we wish to can at home—especially tomato products, the pH of the soil and water we grow our vegetables in, and a few medical conditions.  Now we’ll look at whether we want to get strips, a meter, or both.

The pH Scale

Back in high school chemistry class, we learned about the pH scale, which covers a range from 0 to 14. 

• 0-7 acidic
• 7  neutral
• 7-14 alkaline (or basic)

We also learned that the pH scale is logarithmic (just like the Richter scale used for measuring earthquakes), and that each 1.0 unit change reflects a difference by an order of magnitude, or a factor of 10.  In other words, the hydrogen ion activity, or pH, at pH 4.0 is ten times greater than at pH 5.0.

The two methods for testing pH are strips and meters.

pH Test Strips

When you go to Amazon to buy your test strips, make sure the strips test the range that you need.  The vast majority of strips on amazon test the 1-14 range, and you can get enough to last the duration of doom for less than $10.  However, these may not be the strips you want.  Shorter range strips (put “short range” in the search bar), like in the 3.0-5.5 range, are more ideally suited for testing food safety for water bath or pressure canning.  Of course, these are going to be more expensive, but not prohibitively so, about $10 for a 15-foot roll, which contains 180 1” test strips.  You’ll be able to test a lot of canned goods.  If you wish to test garden soil and hydroponic solutions, you’ll need a different range of strips, like the 4.5-8.5 range. 

After purchase, upon receipt of the test strips, conduct your own test to make sure they work.  Some of the test strips coming from China are worthless.  Check vinegar, lemon juice, bleach, soap, water, maybe some canned foods when you open them. 

The pH testing strips are really easy to use.  Follow instructions on the package, as some strips are only placed in the solution for a second or so, while others must remain in the solution for up to 20 seconds.  Simply dip strip into the food, soil or hydroponic solution, or urine, wait the requisite time, and then match the color of the strip to manufacturer’s color chart on the bottle or package.  You’ll get a pretty good idea of your pH using these strips.

The advantages of these paper strips are that they are very inexpensive and can be purchased in bulk.  Unfortunately, the results are not super specific—you don’t get an exact pH value.  They must be used in good light and LED lighting can affect the color appearance.  Other disadvantages are that color perception can also be affected by colors nearby.  And if your product has a strong color, like tomato sauce or salsa, it may make reading the result accurately difficult or impossible.

Digital pH Meters

Digital pH meters are even easier to use than the litmus paper strips.  You simply uncap the meter (always keep the cap on when not in use), power it on, dip it in the solution being tested for a few seconds, and read the result.  Rinse and re-cap. 

The advantages of the digital meters are that you get a precise pH reading that isn’t affected by lighting or adjacent colors, and works even when dealing with tomato products.  It is only a few dollars more than the pH strips, currently selling for about $15 on Amazon, and it tests the entire range of pH, whether you need the safe canning range at the lower end of the scale or the gardening or medical ranges that are closer to neutral. 

The disadvantages are that the digital meter needs regular cleaning and occasional calibration.  It also needs to be carefully stored.  As it runs on a battery (and as I look at mine, it doesn’t look easy to replace the battery—they probably want you to buy a new one when it needs to be replaced), it won’t last forever. 

In conclusion, I feel being able to assure the safety of my home canned tomato products and monitor soil and hydroponic solutions definitely warrants having a means of testing the pH.  I like having the digital meter because it is so precise for checking the foods, but I also like having the strips as a backup and for quick checking of hydroponic solutions where precision is not so critical. 

Links to related posts:

pH Primer for Preppers, Part 1—Canning

pH Primer for Preppers, Part 2—Gardening and Medicine

Start Right to End Right—3 DIY Soil Tests

References:

https://blog.bluelab.com/pros-and-cons-of-ph-testing-strips-for-growing

https://www.wikihow.com/Read-pH-Strips

https://aperainst.com/blog/why-choose-a-ph-meter-instead-of-a-ph-test-strip/