I am in the process of installing water treatment equipment in my home. Let's say that I have discovered that used car salesman do not have a thing on water treatment salesmen. I was told that my water had 6+ grains per gallon (103+ ppm) of hardness, depending on who was giving the sales pitch (all testing was performed offsite by the companies attempting to sell me a system). The iron levels quoted were between 0.3 and 0.5 ppm. I have never smelled or tasted iron in my water, nor have I ever experienced staining in my sinks; therefore, the quoted iron values set off my "upsale" alarm.
I decided to run my own tests after conferring with Martin B. I needed know the actual average hardness of the water that my well produces because an acid-neutralizing filter (ANF) will add 3 to 4 grains per gallon (51 to 68ppm) of hardness. Ten grains per gallon is high enough to warrant installing a water softener. For various reasons, I would like to avoid having to install a water softener. In fact, having to install a water softener is the reason why I have avoided installing an ANF up to this point.
I started with two different strip-based kits. The kits confirmed that my water hardness was below 103ppm. Neither of the kits detected iron. Desiring more accuracy, I decided to purchase Hanna's 3812 hardness test kit, which is your typical titration-based hardness test kit. The resolution of this kit is 30ppm. I barely injected 0.2ml of EDTA (60ppm) before the color change occurred. I ran this test several times over a period of two weeks, and the results were the same.
I ordered a Hanna Checker HI 721 iron colorimeter at the same time that I purchased the Hanna 3812 hardness test kit. Hanna’s colorimeters are the cat's pajamas for guys like me who have difficulty with hue discrimination. The only thing that I do not like about the HI 721 meter is the powdered reagent packaging. It is difficult to pour the powdered reagent into the glass cuvette (vial). The HI 721 has a range from 0.00 to 5.00 ppm with a resolution of 0.01ppm and an accuracy of +/- 0.04ppm. The level of iron in my water is at or below the error level of the meter, which was strike number two for the water treatment salesmen.
Hanna HI 721 Iron Colorimeter
While awaiting the hardness test kit and iron colorimeter to arrive, I decided to research the geology of my property. I was able to identify the rock formation on which my property resides as well as the average grains per gallon hardness for the area using the USGS website. This information is important because the rock formation that underlies a given piece of land usually determines the mineral content of its ground water. My property lies within a rock formation that is composed of muscovite-chlorite-schist. Muscovite-chlorite-schist is a metamorphic rock. Anyone who has read Water
by Palmer and Kaminski knows that this type of rock falls into the fifth type of aquifer outlined in the book. Wells in my area are deep fractured rock wells. Because the water filters through fissures in metamorphic rock, wells produce water with low amounts of dissolved minerals. This information correlated with my findings. The important thing that I learned from reading Water
was that the hardness of a type five aquifer remains fairly constant throughout the year due to the insolubility of the rock formation.
The final reading that I wanted to obtain was alkalinity. My positive experience with the Hanna HI 721 iron colorimeter led me to purchase the Hanna HI 775 freshwater alkalinity colorimeter (Hanna also produces the HI 755, which is a saltwater alkalinity meter). Let's say that I knew that my water was low in alkalinity due to its pH; however, I was completely blown away by how low the alkalinity actually measured. I drew several samples over a period of a week, and the alkalinity readings held at around 25pmm. That figure combined with Martin B's spreadsheet highlighted the fact that I need to add a source of bicarbonate when making calcium additions to my brewing water due its low buffering capacity (i.e., the residual alkalinity goes negative very quickly).
Hanna HI 775 Alkalinity Colorimeter
In closing, I know that I could have just sent a water sample to Ward Labs. However, I would have missed out on an important learning opportunity. Additionally, I went into the exercise knowing that the quality of a water supply can periodically change from brewing at my prior residence; therefore, a one-time snapshot of one’s water supply can make brewing water adjustments a hit or miss proposition. The water at my prior residence was provided by a public utility. The water composition changed dramatically between the winter and summer months when the county switched from artesian aquifers to purchasing surface water from a neighboring city's reservoirs. The water from the artesian aquifers produced great beer after the public utility treated it with hydrated lime (a.k.a. Ca(OH)2). The surface water produced beer that was not nearly as good, which is why I stopped brewing in May every year.