Neither. Baking soda raises the Total Alkalinity. Soda ash raises the pH.
Chlorine will not raise the total alkalinity level in a pool. However, if you are trying to raise the total alkalinity, you can add small amounts of baking soda.
the pH can be raised by adding an alkaline chemical such as soda ash (which also raises total alkalinity quite a bit) or borax (which has only a slight effect on total alkalinity), or by aeration of the water to outgas CO2 (which will raise pH with no impact on total alkalinity). Soda ash actually has very little effect on Total Alkalinity. Baking soda is the chemical to use to raise T/A.
Yes, to raise total alkalinity. It will not raise pH Total alkalinity (TA) is a buffer for pH. the higher the TA in a pool the harder it is to get the pH to move.
Alkalinity is not an actual "chemical", however if you are concerned about increasing the alkalinity in your swimming pool, you are perfectly safe. The chemical that increases "total alkalinity" in a swimming pool, is only baking soda. It wil not harm the human body!
The recommended pH for pools is 7.2 - 7.8. Sodium bicarbonate or soda ash will raise the pH. Sodium bicarbonate (baking soda) will raise the Total Alkalinity. Soda ash (sodium carbonate) will raise the pH. They are not interchangeable.
Usually, but not always, low Total Alkalinity (T/A) and low pH go hand in hand. Soda ash (sodium carbonate) will raise the pH without significantly affecting T/A and baking soda (sodium bicarbonate) will raise Total Alkalinity without significantly affecting the pH.
Bicarbonate will RAISE the pH and total alkalinity.
Baking soda will not soften (remove calcium hardness) from pool water. It will raise total alkalinity.
Baking soda can be used to control acidity in swimming pools. Baking soda controls the Total Alkalinity Soda ash raises the pH or reduces the acidity.
Short answer yes. Baking soda is Sodium Bi-carbonate and it is used to increase your total Alkalinity. Some people even use it to raise their PH.
With the addition of muriatic acid.