🧂 Dichlor Granules (56%)
granular sodium dichloro-s-triazinetrione, ~56% available chlorine · updated August 2026
Quick answer: add 2.4 oz per 10,000 gallons to raise Free Chlorine 1 ppm. Ideal Free Chlorine: 1–3 ppm (shock: 10–12 ppm). Add ½–⅔ first, circulate, retest.
Safety — read first
- • Never mix with cal-hypo or any other chlorine product in dry form.
- • Broadcast over the deep end with the pump running.
Stabilized granular chlorine — pH-neutral and gentle on surfaces, but every dose also raises your stabilizer. Best for new fills and spas.
Side effects: Adds ~0.9 ppm CYA per 1 ppm FC — CYA builds up fast. Fine early season, switch to liquid or cal-hypo once CYA hits 30–50.
Dosing chart
| Pool size | +1 ppm | +2 ppm | +5 ppm | +10 ppm |
|---|---|---|---|---|
| 5,000 gal | 1.2 oz | 2.4 oz | 6.0 oz | 12.0 oz |
| 10,000 gal | 2.4 oz | 4.8 oz | 12.0 oz | 1.5 lb |
| 15,000 gal | 3.6 oz | 7.2 oz | 1.1 lb | 2.3 lb |
| 20,000 gal | 4.8 oz | 9.6 oz | 1.5 lb | 3.0 lb |
| 30,000 gal | 7.2 oz | 14.4 oz | 2.3 lb | 4.5 lb |
Calculate your exact dose
1 · Your pool's volume
Working with 20,000 gallons
2 · What are you fixing?
Ideal Free Chlorine: 1–3 ppm (shock: 10–12 ppm). Adjusting pH? Doses aren't linear — see soda ash / muriatic acid.
3 · Add one of these
Slightly raises pH. Loses strength in storage — buy fresh, store cool and dark.
Adds ~0.7 ppm calcium hardness per 1 ppm FC — avoid if your CH is already high. Slightly raises pH.
Adds ~0.9 ppm CYA per 1 ppm FC — CYA builds up fast. Fine early season, switch to liquid or cal-hypo once CYA hits 30–50.
Adds ~0.6 ppm CYA per 1 ppm FC and is strongly acidic — expect pH and alkalinity to drift down with steady tab use.
Estimates from standard label dosing, to raise Free Chlorine by 2.5 ppm in 20,000 gallons. Add ½–⅔ of the dose first, circulate 4–6 hours, retest, then top up. Never mix chemicals with each other.
FAQ
How much dichlor granules do I add per 10,000 gallons?+
2.4 oz per 10,000 gallons will raise Free Chlorine 1 ppm. Scale linearly with your pool size — the chart on this page covers 5,000 to 30,000 gallons.
What does dichlor granules do to a pool?+
Stabilized granular chlorine — pH-neutral and gentle on surfaces, but every dose also raises your stabilizer. Best for new fills and spas. Side effect to know: Adds ~0.9 ppm CYA per 1 ppm FC — CYA builds up fast. Fine early season, switch to liquid or cal-hypo once CYA hits 30–50.
Is dichlor granules safe to handle?+
Never mix with cal-hypo or any other chlorine product in dry form. Broadcast over the deep end with the pump running.