Total alkalinity is pH's shock absorber — when it's low, pH bounces around. Here's how to raise it with baking soda, dosed for your gallons.
Total alkalinity (TA) buffers pH, keeping it stable. Aim for about 80–120 ppm. When TA is low, pH swings unpredictably with every rain or chemical addition; when it's in range, pH holds steady. The calculator above opens on the Raise Alkalinity mode — enter your gallons and current TA for the baking soda dose.
Baking soda (sodium bicarbonate) is the standard for raising TA — the same product sold in bulk as "alkalinity increaser." Broadcast it across the surface with the pump running; it dissolves readily. It raises alkalinity strongly and pH only slightly, so it's the right tool when TA is your problem. Add in stages for large corrections and retest after circulating.
These two move together and confuse a lot of pool owners. Rule of thumb: correct total alkalinity into range first, then fine-tune pH. If you chase pH while alkalinity is off, it won't stay put. If your TA is too high instead, that's corrected with acid — see lowering pH, since acid lowers both.
About 80 to 120 ppm for most pools. Salt and some surfaces do best nearer the lower end. In range, alkalinity keeps pH stable.
Yes — commercial alkalinity increaser is sodium bicarbonate, the same compound as baking soda. Buying baking soda in bulk is usually cheaper for the same result.
Roughly 1.4 lb per 10,000 gallons raises total alkalinity about 10 ppm. Enter your pool volume and current and target TA in the calculator above for a specific amount.