How many gallons is a 20x40 pool?
About 32,912 gallons at 5.5 ft of water. Inground pools this size usually run 3.5 ft to 8 ft deep, which averages about 5.5 ft.
| Average depth | Gallons | Liters |
|---|---|---|
| 4.5 ft | 26,928 | 101,922 |
| 5.5 ft | 32,912 | 124,572 |
| 6.5 ft | 38,896 | 147,221 |
Chemical doses for 32,912 gallons
| To do this | Use | Amount |
|---|---|---|
| Raise free chlorine 1 ppm | Liquid chlorine 12.5% | 34 fl oz |
| Shock from 1 to 16 ppm (CYA 40) | Liquid chlorine 12.5% | 3 gal 122 fl oz |
| Shock from 1 to 16 ppm (CYA 40) | Cal-hypo 65% | 6 lb 5 oz |
| Salt from 0 to 3,200 ppm | Pool salt | 877 lb 10 oz |
| Raise alkalinity 10 ppm | Baking soda | 4 lb 10 oz |
These are starting doses. Add, circulate for an hour, retest. For your own readings use the chlorine, shock, salt, pH and alkalinity calculators.
Full dose tables for the nearest round number: shock for a 30,000 gallon pool, chlorine for a 30,000 gallon pool, salt for a 30,000 gallon pool, baking soda for a 30,000 gallon pool.
Other rectangle sizes
12x24 pool, 14x28 pool, 15x30 pool, 16x32 pool, 18x36 pool. Or see every size.