Keeping the right alkalinity level in your hot tub water is important for balancing pH and preventing corrosion or scale buildup. Here’s a quick guide to adjusting alkalinity in a hot tub:
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What is alkalinity in hot tub water?
Alkalinity refers to the ability of water to resist changes in pH. It is a measure of the buffering capacity of water, or the amount of acids or bases needed to change the pH. In hot tubs, alkalinity acts as a stabilizer to prevent rapid changes in pH which can damage equipment and be uncomfortable for bathers.
What is the ideal alkalinity level?
The recommended alkalinity level for hot tubs is between 80-120 ppm (parts per million). This range provides enough buffering capacity to keep the pH stable, without being so high that it resists pH changes too much.
How do I test alkalinity in my hot tub?
You’ll need an alkalinity test kit or test strips specifically designed for hot tubs. Follow the directions to get an alkalinity reading in ppm. Test alkalinity weekly.
How do I raise alkalinity?
To increase low alkalinity, add sodium bicarbonate (baking soda) to the hot tub water. Add in small increments of 1/2 teaspoon per 100 gallons of water at a time. Allow circulating for 30 minutes before retesting and adding more if needed. Don’t add more than 2 teaspoons per 100 gallons at a time.
How do I lower alkalinity?
To decrease high alkalinity, dilute the water by draining some out and adding fresh water. Another option is to add sodium bisulfate (pH decreaser). Add about 1/2 teaspoon per 100 gallons and retest after allowing to circulate for 30 minutes before adding more.
Tips for maintaining proper alkalinity
- Test alkalinity weekly and adjust as needed to keep between 80-120 ppm.
- Make alkalinity adjustments before adjusting pH.
- Rinse filters regularly to prevent buildup of alkaline particles.
- Add alkaline increaser after adding acidic chlorine or bromine sanitizers.
- When adjusting, retest after allowing time to circulate rather than adding too much at once.
Conclusion
Checking and adjusting the alkalinity is important for hot tub water balance. Test alkalinity weekly and add baking soda to increase or sodium bisulfate to decrease as needed to maintain levels between 80-120 ppm. With the right alkalinity range, pH will hold steady and prevent water chemistry issues. Consistent testing and small incremental adjustments are key to keeping your hot tub water in balance.