Many have heard the term “hard water” before, but few know what hard water actually is. Hard water is essentially water with a high dissolved mineral content, with high concentrations of calcium and magnesium. Hard water occurs when regular water collects these dissolved minerals in its journey from rain water to underground aquifers. Due to the fact that the dissolved minerals need to be picked up overtime by the water, it is most often that water sources such as a well have the highest mineral content. A water source such as a lake or reservoir is fed majorly by precipitation and rain, and therefore generally avoids contact with the minerals that cause water to be “hard.”

Hard water is not a health hazard, but has detrimental household side effects: hard water can prevent soaps and detergents from properly working, and results in deposits of calcium carbonate, calcium sulfate, and magnesium hydroxide inside of pipes and boilers which lowers the water flow and consequently creates less efficient appliances and heating systems. When soap interacts with hard water, the calcium and magnesium react with the sodium in soap. The sodium salts present in soaps are converted to their corresponding calcium and magnesium salts which are precipitated as scum. The insoluble scum sticks on the clothes and so the cleaning capacity of soap when hard water is present is significantly decreased. When there is no softener combined with the laundry, this scum noticeably shows up on clothes, giving it all a white tint. Hard water also causes hair damage and skin damage, so, all considered, households with hard water aim to eliminate it.

Water softening is a process where the ions of calcium and magnesium are removed. These ions are what make it difficult for products with other positively charged ions to dissolve in the water.. Water can be chemically softened on a large scale through the addition of lime to precipitate the calcium as carbonates and the magnesium as hydroxide, where sodium carbonate is added to remove any remaining salt deposits. Essentially, water softening is achieved by forming insoluble precipitates, chemically, or by ion exchange. On a smaller scale, the method of using borax works to soften the water.

The purpose of this experiment was to first determine whether borax is successful at softening water, and secondly to determine how much borax is required to fully soften water. Throughout preliminary research and testing, it was confirmed through the water hardness test that borax was an effective method of water softening. Preliminary and final testing meshed together, as my goal was to find the amount of borax necessary to soften 200mL of water, so the beginning of any testing was the beginning of final testing.

First, using the directions on the water testing kit, the hardness of only tap water was measured. After the hardness was found, the rest of the experiment’s goal was to find how much borax would soften the Milton Academy tap water. In preliminary research it was found that some amount of borax between .75 and 1 gram of borax would soften 200mL of water. To test one amount of borax in the water, 200mL of tap water was poured into a beaker. The borax was then measured in a petri dish on a scale. The petri dish was placed on the scale and the scale was zeroed. The borax was then measured on the zeroed scale. The borax was poured into 200mL of water, and was mixed until the borax was completely dissolved in the water. Then, the test kit was used to see if it was blue, meaning soft, or purple, meaning it was still hard.

The results of this experiment consist of one number: essentially, .83 grams of borax is needed to successfully soften 200mL of water. This water softening is done on Milton Academy's 120ppm water, which is considered quite hard on the hard water scale. Given this amount of borax that is needed to soften 200mL of water that is 120ppm hard, the amount of borax needed for one load of laundry to successfully soften the water was found. There are 3785.41 mL in a gallon, which means that 3141.89 grams of borax is needed per gallon. This means, with the data collected in this experiment, that 354.23 cups of borax is necessary in order to soften the water in a load of laundry. While perhaps this is an overestimation, the general verdict is that much more borax is required to soften water than one would predict. While the packaging reads ½ cup of borax being necessary for a load of laundry, this would only reduce the scum that lands on clothes, and will not remove the minerals altogether. As this is so, despite borax’s water softening capabilities, it is not a very efficient method of softening water; borax instead can be viewed as a deterrent of the scum that hard water produces on clothing rather than a solvent for hard water.

Alternatively, a hard water softening system is the most effective way of softening water. The process of ion exchange that whole-home water softeners initiate removes all magnesium and calcium from the water. The water flows through a water softener tank of spherical beads that are made with polystyrene and are negatively charged with sodium ions. When the positively charged calcium and magnesium ions in water interact with the negatively charged resin beads, the magnesium and calcium is effectively removed from the water.

After seventeen years of having hard well water and using a water softener at my house, I finally understand what hard water is, and what softening the water consists of. The high dissolved mineral content of hard water makes it detrimental to many components of homes and the people that live in the homes, and, after exploring ways of softening it, it was determined that .83 grams of borax was effective in the softening 200mL of water. Borax, however, is not a very efficient solution to softening water. Rather, a house-wide water softener should be used. After a conversation with Ms. Zimmer, a future experiment that would further explore hard water at Milton would be testing the water hardness across an entire year. This experiment was inspired by Ms. Zimmer’s observation that the water seems to come out more cloudy after the pipes receive their yearly “flush.” This cloudiness could certainly be minerals that flushing the pipe system caused to be stirred around, resulting in a higher water hardness at some times in the year and softer water once the minerals have settled. It would be interesting to observe whether or not the water hardness actually changes, because the current water hardness levels at Milton Academy are 120ppm, which is quite elevated.

https://www.britannica.com/technology/water-softening

https://homesteady.com/12465154/how-to-use-borax-as-a-water-softener

http://amrita.olabs.edu.in/?sub=73&brch=3&sim=120&cnt=1

https://www.luminoruv.com/education/softening/

https://www.mcgill.ca/oss/article/health-you-asked/you-asked-hard-water-dangerous-drink#:~:text=Hard%20water%20can%20interfere%20with,making%20for%20less%20efficient%20heating.