The pH of water refers to its alkalinity or acidity. A value less than 7 always denotes acidic conditions, while a value greater than 7 denotes alkaline conditions. A value of 7, on the other hand, represents the neutral state. Since pH measures the number of free hydrogen ions in a solution, it is influenced by water parameters such as general hardness and carbonate hardness. The pH of Corey and Morgans tap water is 7.8, and for the fish to survive in the aquarium, they must lower the pH to acidic conditions preferably between 5.5 and 6.5. When lowering the pH of aquarium water, it is vital to do it slowly so that fish can acclimatize. API pH down contains sulphuric acid, which as per Almeida et al. (359) is a very strong acid with a pH of 2.75. Therefore, it is an option that Corey and Morgan can consider to lower the pH of the system.
Besides, API pH down acts fast and is colorless which implies that it will not color or cloud the aquarium water. Additionally, it does not contain nitrate and phosphate and as such, will not encourage the growth of algae (Liebherr). However, white vinegar contains 5% acetic acid and has a pH of 2.4, and this makes it the best option to lower the pH of the system (Budak). The first step is to test the pH of the tap, which as stated earlier is 7.8. A blue litmus paper will turn red under acidic conditions while the red litmus will turn blue in basic conditions. When the acetic acid in white vinegar combines with water and oxygen, it converts to water, carbon dioxide, and bicarbonate.
This increase in the concentration of carbon dioxide will reduce the pH of the water in the aquarium. Thus, the process is known as ionization whereby the acetic acid releases hydrogen ions, and after several hours bacteria and other organisms metabolize the acetic acid using oxygen and releasing carbon dioxide. According to Budak, to allow for proper dilution, the recommended quantity is 1ml of vinegar in every gallon of water added (Budak). It is, however, vital to note that too much carbon dioxide in water and reduction of oxygen can also be damaging to the fish.
Therefore, while using white vinegar to reduce the aquariums pH, it is imperative to measure the acidity and alkalinity using a litmus paper several hours after adding the vinegar. Corey and Morgan must begin the process with small amounts of white vinegar to allow enough time for the system to stabilize and equalize before attempting to add more vinegar. The advantage of using vinegar lies in the fact that it is a natural product as opposed to API pH down and as such, it is non-toxic and works without leaving a residue (Budak). Overall, lowering the pH, of the aquarium depends on the size of the tank and getting the right quantity.
Almeida, João, et al. “Molecular understanding of sulphuric acid-amine particle nucleation in the atmosphere.” Nature502.7471 (2013): 359-363.
Budak, Nilgün H., et al. “Functional properties of vinegar.” Journal of food science 79.5 (2014).
Liebherr, Bailey, et al. “The Effects of pH on Algae Cell Growth in Water.” Journal of Introductory Biology Investigations 5.3 (2016).