How much sodium bicarb should you use for a 15000 gal pool?

To calculate the amount of sodium bicarbonate (baking soda) you should use for a 15,000-gallon pool, follow these steps:

1. Determine the desired alkalinity level: The ideal alkalinity level for a swimming pool is between 80 and 120 ppm (parts per million). If you're not sure what the current alkalinity level of your pool is, you can test it using a pool water test kit.

2. Calculate the alkalinity deficit: If the current alkalinity level is below the desired level, you need to calculate the deficit. For example, if the current alkalinity level is 60 ppm and you want it to be 100 ppm, then the alkalinity deficit is 40 ppm (100 ppm - 60 ppm).

3. Determine the amount of sodium bicarbonate needed: Each 1 pound of sodium bicarbonate raises the alkalinity level of 10,000 gallons of water by about 10 ppm. So, to raise the alkalinity level of a 15,000-gallon pool by 40 ppm, you would need:

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15,000 gallons / 10,000 gallons x 40 ppm / 10 ppm = 6 pounds

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Therefore, you would need 6 pounds of sodium bicarbonate to raise the alkalinity level of a 15,000-gallon pool from 60 ppm to 100 ppm.

Note: It's always best to add chemicals slowly and gradually to your pool, rather than all at once. This can help to prevent any adverse effects on the pool water chemistry.