Baking soda or sodium bicarbonate is a chemical compound with formula NaHCo3 . Baking soda is most commonly used while baking, cooking and even for cleaning. It also helps provide relief from acid reflux and indigestion. There are several other uses of baking soda. It is often added to swimming pool water, water in a fish tank and so on. You would want to know if adding baking soda lowers the pH in water.
pH levels are a measure of acidity or alkalinity of a solution. If pH of liquid is lower then that solution is acidic and when pH is higher the solution is alkaline. pH scale ranges are from 0 to 14. Usually pure water is neutral with pH levels of around 7. However, there are factors that cause pH of water to alter. Usually high pH of water is due to the dissolved solids and mineral ions. Such water is referred as hard water. Hard water is often the cause of stains on appliances, laundry, etc. It is mostly not suitable for use.
Baking soda does not lower the pH in water but is useful in raising the pH. If you want to make it safe for you to use the swimming pool water with pH levels higher than they are, then adding baking soda helps raise the pH in water. Similarly, when you have some fish in the aquarium at home you may find it necessary to modify the pH value and the hardness. For some species of fish, it has been found that tap water is not suitable.
Taking the example of fish, if you have the African Rift valley cichlids, the water hardness and pH levels will have to be changed. To do that you need equal parts of baking soda, Epsom salts and calcium chloride or marine salt mix. You can achieve a pH value of up to 8.2 with sodium bicarbonate (baking soda) ions. The Epsom salt and calcium chloride can be used to increase the water hardness. Only remember and be cautious when you play around changing the pH and hardness levels. If water conditions become unstable it may prove fatal for the aquarium fish. It is Epsom salt that is useful in making water softer, i.e. reducing hardness of water. If you add baking soda to de-chlorinated water from the aquarium, it may cause short term drop of pH. However, it will gradually bring up the pH to 8.2. Baking soda should be used to buffer the drop in pH levels when you trying to adjust the levels as it may be harmful to your fish.
Water that is used for drinking should preferably have a pH level between 6.5 and 8.5. If the levels go beyond 8.5, it means there are high levels of alkalinity minerals in it. Though it is not harmful for health, you will find an alkali taste to water. If the pH is lower then water is acidic, it is naturally soft. It can leach metals like copper, lead and zinc from your pipes and plumbing which may be harmful.
Baking soda cannot be used to lower the pH of water. It is most commonly used to increase the pH levels and also help buffer drops in levels when you are trying to adjust water quality to suit the needs of swimming pools and aquariums.