Frequently Asked Questions

Most in-ground pools hold between 10,000 and 25,000 US gallons — a 15 × 30 ft pool at a 5 ft average depth holds about 16,800 gallons (63,600 litres). To find yours, enter your shape and dimensions in our pool gallons calculator and get an exact figure instantly, no guessing from charts.

Pool size usually means surface area — multiply length × width in feet, so a 15 × 30 ft pool is 450 sq ft. Capacity is separate: surface area × average depth × 7.48 gives gallons. Measure the water's longest and shortest sides for area, then add average depth in our pool size calculator for volume.

450 square feet. Surface area is simply length × width: 15 × 30 = 450 sq ft. With a 5 ft average depth, that footprint holds about 16,800 US gallons (63,600 litres) — handy for chemical doses measured per 10,000 gallons.

200 sq ft is a small-to-medium backyard pool — common shapes are a 10 × 20 ft rectangle, roughly 12 × 17 ft, or a 16 ft round pool (about 201 sq ft). At a 5 ft average depth it holds roughly 7,480 US gallons (28,300 litres).

600 sq ft is a large pool — typical layouts are 20 × 30 ft, 15 × 40 ft, or 18 × 33 ft. With a 5 ft average depth it holds about 22,440 US gallons (85,000 litres). Calculate any rectangle with length × width for area, then area × average depth × 7.48 for gallons.

Liquid chlorine (sodium hypochlorite, sold at 10–12.5%) dosing depends on strength — 12.5% delivers about 25% more chlorine than 10% per volume. Work out the dose from your pool gallons and the ppm rise you need, then match it to the percentage on the bottle. Our liquid chlorine calculator returns the exact pour for your volume, current level and target level.

Most salt chlorinator systems target 3,200 ppm — that works out to about 27 lbs of pool-grade salt per 1,000 gallons for a full fill, so a 15,000-gallon pool needs roughly 400 lbs (180 kg) from zero. Top-ups are much smaller: enter your volume and current level in the salt pool calculator, then run the pump 24 hours to dissolve it.

Baking soda (sodium bicarbonate) raises total alkalinity by about 10 ppm per 1.5 lbs per 10,000 gallons — aim for 80–120 ppm. A 10,000-gallon pool sitting at 70 ppm needs roughly 4.5 lbs to reach 100 ppm. Enter your volume and readings in our pool chemical calculator, add it with the pump running, and retest after 4–6 hours.