📈 Soda Ash
sodium carbonate ('pH Up') · updated August 2026
Quick answer: add 6 oz per 10,000 gallons to raise pH by ~0.2 (at TA ≈ 100 ppm). Add ½–⅔ first, circulate, retest.
Safety — read first
- • Pre-dissolve in a bucket — dumping it in directly can cloud the water.
- • pH response depends on your alkalinity; add ⅔ of the calculated dose and retest.
The pH raiser. pH chemistry is non-linear, so treat doses as starting points: ~6 oz per 10,000 gallons raises pH about 0.2 when alkalinity is near 100 ppm.
Side effects: Also raises alkalinity (~5 ppm TA per 6 oz/10k gal). If both pH and TA are low, baking soda may fix both.
Dosing chart
| Pool size | 0.1 pH | 0.2 pH | 0.3 pH | 0.5 pH |
|---|---|---|---|---|
| 5,000 gal | 1.5 oz | 3.0 oz | 4.5 oz | 7.5 oz |
| 10,000 gal | 3.0 oz | 6.0 oz | 9.0 oz | 15.0 oz |
| 15,000 gal | 4.5 oz | 9.0 oz | 13.5 oz | 1.4 lb |
| 20,000 gal | 6.0 oz | 12.0 oz | 1.1 lb | 1.9 lb |
| 30,000 gal | 9.0 oz | 1.1 lb | 1.7 lb | 2.8 lb |
pH dosing is non-linear — the response depends heavily on your total alkalinity. These figures assume TA ≈ 100 ppm; add ⅔ of the dose and retest after 4–6 hours.
FAQ
How much soda ash do I add per 10,000 gallons?+
6 oz per 10,000 gallons will raise pH by ~0.2 (at TA ≈ 100 ppm). Scale linearly with your pool size — the chart on this page covers 5,000 to 30,000 gallons. pH response depends on your alkalinity, so treat this as a starting point and retest.
What does soda ash do to a pool?+
The pH raiser. pH chemistry is non-linear, so treat doses as starting points: ~6 oz per 10,000 gallons raises pH about 0.2 when alkalinity is near 100 ppm. Side effect to know: Also raises alkalinity (~5 ppm TA per 6 oz/10k gal). If both pH and TA are low, baking soda may fix both.
Is soda ash safe to handle?+
Pre-dissolve in a bucket — dumping it in directly can cloud the water. pH response depends on your alkalinity; add ⅔ of the calculated dose and retest.