How Much Chlorine for a 300 Gallon Hot Tub?
Chlorine amounts for a 300 gallon hot tub or spa.
Recommended chlorine for hot tubs
Keep 3–5 ppm free chlorine. Run jets 15–20 min after adding.
Chlorine dosage (from 0 ppm)
| Chlorine increase | Liquid (10%) | Granular |
|---|---|---|
| 1 ppm | 0.0 oz | 0.0 oz |
| 2 ppm | 0.0 oz | 0.1 oz |
| 3 ppm | 0.0 oz | 0.1 oz |
| 4 ppm | 0.0 oz | 0.1 oz |
| 5 ppm | 0.0 oz | 0.1 oz |
Quick calculator
For your exact levels, use our Hot Tub Chlorine Calculator.
FAQ
How much chlorine should a hot tub have?
Keep 3–5 ppm for hot tubs. Test daily and add chlorine as needed.
How often do I add chlorine to a hot tub?
Add chlorine after each use and at least every few days. Run jets 15–20 minutes after adding.