Carbon Dioxide Makes Alkaline Water – Experiment
Written by Dr. Klaus L.E. Kaiser
Anyone can do this experiment and prove that carbon dioxide (CO2) increases the pH of natural water systems.
If you read the statements of carbon dioxide “war mongers”, including those from EPA, you are led to believe that CO2 causes acidification of water. That is true under aseptic conditions such as in a laboratory with distilled water, but not in nature. In nature, there are two crucial differences: the presence of nutrients and sun light. Together, they make a big difference as you will see for yourself by undertaking this simple experiment.
The idea of this experiment is to prove that carbon dioxide in the atmosphere INCREASES the pH of water.
Supplies & Ingredients
A transparent glass or plastic container (flask, container) with a tight-closing lid. [I am using one of those 1-quart plastic containers used in supermarkets for bulk food items, etc.].
A small amount of common plant fertilizer. [I am using a 20-20-20 type all-purpose plant fertilizer].
Distilled or de-ionized water, available in any drug store and most supermarkets.
A way to measure pH of the water [I am using pH sticks; see also bottom note].
A sunny place near your home (inside or outdoors).
A few weeks of time.
What to Do
There is very little to do; the sun does most of the work. Also, please note all of the quantities and concentrations mentioned do not need to be exact; they are just general guidelines.
Fill your container about two-thirds with the water. Keep the lid off and let it stand a comfortable temperature for a few days.
Then measure the pH of the water. It should stabilize near pH 4.5 (weakly acidic).
Add fertilizer at the appropriate rate for the amount of water in your container as per instructions by the manufacturer (commonly a teaspoon for 4 liters or a gallon) and stir until it is dissolved.
Check the pH again; it should not have changed.
Add a smidgen (barely visible amount) of soil, or pond algae as an inoculum.
Tightly close the lid and place the container at a sunny spot.
Wait a few weeks (say 3 to 6 weeks, depending on area, temperature and sunshine).
Once you see obvious signs of algae growing in the container (discoloration of the dye coming with the fertilizer) and turbidity (slime or particles in the system), check the pH again. It will have increased to approximately pH 8.
You have finished the experiment.
You will have demonstrated the conversion of carbon dioxide (from the air) together with the nutrients (the fertilizer you added) and sun light (radiation energy) to plant matter. Of course, nature does this all over without you doing anything at all. Minerals in rocks and soils slowly dissolve and the sun does the rest.
Initially, the distilled water contained no minerals and its pH was determined solely by the dissolution of carbon dioxide from air into the water. The resulting solution of carbonic acid has a pH of approximately 4.5.
Once you added the nutrients (plant fertilizer), added a smidgen of inoculum and waited a few weeks, things had changed dramatically.
The critical result of your experiment is the INCREASE in the pH of the water in your container from the initial 4.5 (carbonic acid solution) to the natural pH of 8 or higher. A pH value of 4.5 is definitely somewhat acidic and a pH of 8 is definitely somewhat alkaline (the opposite of acidic). This happened because the energy of the sun light allowed the algae to reduce the carbonic acid and form alkaline plant matter from it and the nutrients. That is why almost all natural water bodies (lakes, rivers, oceans) are alkaline (with a pH around 8) and not acidic, despite increasing atmospheric CO2 levels.
Contrary to what many people claim about the “acidification effect” of carbon dioxide, nature quickly turns it around and uses CO2 to produce organic matter that makes the water alkaline. The increase in pH was obtained from the conversion of an acidic solution of carbon dioxide and the nutrients with the help of the sun’s energy via the photosynthesis process to alkaline water. You demonstrated it yourself.
Oh, I almost forgot: Your experiment also produced an important by-product, namely molecular oxygen which we need to breathe to sustain life. You may have breathed in some of these molecules already.
Note regarding the pH measurement: It can be measured in various ways. If you have access to a scientific measurement device (via your children’s school, for example) that’s great. If not try to purchase some “pH sticks” (color indicator strips) which are available from various suppliers. Make sure they allow you to measure the pH range from 4.0 to 8.0 in 0.5 unit increments. If you have difficulties obtaining such, send me a self-addressed stamped envelope and I will mail you some.