Dose for one step, by pool size
| Change | Product | 5k gal | 10k gal | 15k gal | 20k gal | 30k gal |
|---|---|---|---|---|---|---|
| Free chlorine +1 ppm | Liquid chlorine 12.5 % (fl oz) | 5.4 | 10.7 | 16 | 21.4 | 32.1 |
| Free chlorine +1 ppm | Bleach 6 % (fl oz) | 11.2 | 22.3 | 33.5 | 44.6 | 66.9 |
| Free chlorine +1 ppm | Cal-hypo 65 % (oz) | 1 | 2 | 3 | 4 | 6 |
| Free chlorine +1 ppm | Dichlor 56 % (oz) | 1.2 | 2.4 | 3.6 | 4.8 | 7.2 |
| Free chlorine +1 ppm | Trichlor 90 % (oz) | 0.8 | 1.5 | 2.3 | 3 | 4.5 |
| pH −0.2 (7.8 → 7.6), TA 100 | Muriatic acid 31.45 % (fl oz) | 6.5 | 13 | 19.5 | 26 | 39 |
| pH +0.2 (7.2 → 7.4), TA 100 | Soda ash (oz) | 3 | 6 | 9 | 12 | 18 |
| Total alkalinity +10 ppm | Baking soda (lb) | 0.7 | 1.4 | 2.1 | 2.8 | 4.2 |
| Total alkalinity −10 ppm | Muriatic acid 31.45 % (fl oz) | 12.8 | 25.6 | 38.4 | 51.2 | 76.8 |
| Calcium hardness +10 ppm | Calcium chloride 77 % (lb) | 0.6 | 1.3 | 1.9 | 2.5 | 3.8 |
| Stabilizer (CYA) +10 ppm | Cyanuric acid (oz) | 6.5 | 13 | 19.5 | 26 | 39 |
| Salt +500 ppm | Pool salt (lb) | 20.8 | 41.7 | 62.5 | 83.3 | 125 |
| Borates +10 ppm | Boric acid (lb) | 2.4 | 4.8 | 7.2 | 9.5 | 14.3 |
Every dose scales in a straight line with the step and the gallons: for 3 ppm of chlorine take three times the +1 ppm figure, for a 25,000-gallon pool take the 10k column × 2.5. A 20,000-gallon pool going from 1 to 4 ppm free chlorine needs 3 × 21.4 = 64 fl oz of 12.5 % liquid chlorine. Acid and soda ash are the exception to simple scaling: the same pH change takes more at higher alkalinity, so the pH rows assume a total alkalinity of 100 ppm and the pool pH calculator corrects for yours.
Before you dose
Test first and know your gallons; a wrong volume makes every number above wrong, and the pool gallon calculator saves yours for the other calculators. Add one chemical at a time with the pump running, pour in front of a return, and retest before the next. Never mix chemicals together or add water to acid. Target levels are in the pool chemistry levels chart. Fluid ounces (fl oz) measure volume and ounces (oz) weight; the pool unit conversions page converts both.
Frequently asked questions
How much chlorine do I add per 10,000 gallons?
To raise free chlorine by 1 ppm in 10,000 gallons: 10.7 fl oz of 12.5 % liquid chlorine, 22.3 fl oz of 6 % bleach, 2 oz of 65 % cal-hypo, 2.4 oz of dichlor or 1.5 oz of trichlor. Multiply by the ppm you need: 3 ppm of liquid chlorine is 32 fl oz.
How do I scale a pool chemical dose to my pool size?
Divide your gallons by 10,000 and multiply the per-10,000 figure. A 25,000-gallon pool takes 2.5 times the 10k dose: 1.4 lb of baking soda per 10 ppm becomes 3.5 lb. The same works for the step: 30 ppm instead of 10 ppm means three times the amount.
How much baking soda raises alkalinity by 10 ppm?
About 1.4 lb per 10,000 gallons. A 15,000-gallon pool needs 2.1 lb for 10 ppm and a 20,000-gallon pool 2.8 lb. Baking soda barely moves pH, so it is the product for raising alkalinity alone; soda ash raises pH and alkalinity together.
Why does the same pH change need different amounts of acid?
Total alkalinity buffers pH. At a TA of 100 ppm, 26 fl oz of 31.45 % muriatic acid lowers 20,000 gallons from 7.8 to 7.6; at 50 ppm TA it takes about half. The chart assumes TA 100; the pH calculator takes your own alkalinity.
Can I add several pool chemicals at once?
Add one at a time. Pour each in front of a return with the pump running, let it circulate, and retest before the next; for pH and alkalinity, wait about 30 minutes. Never mix chemicals in a bucket, especially chlorine and acid, and always add chemical to water, not water to chemical.
Every cell is computed by the same functions as the calculators. Dose factors per 10,000 gallons: Trouble Free Pool, Pool School "Pool Math" and product labels (chlorine, acid, soda ash, baking soda, stabilizer, salt); calcium chloride from the molar masses of calcium carbonate and calcium chloride, cross-checked with labels; boric acid from its 17.48 % boron content. Read October 23, 2026.