[mage lang=”en|fr|de|en” source=”flickr”]swimming pool chemicals soda ash[/mage]
Swimming pool chemical question: difference between soda ash and sodium bicarbonate to be used to raise ph?

Typically if the pH is low the Total Alkalinity is also. Always adjust alkalinity first. Bicarb raises Total Alkalinity a lot, and pH a little. Soda ash is used to tweak the pH after alkalinity is raised. It raises pH a lot and Total alkalinity a little. Two different chemicals for two different purposes.