To change the alkalinity in your spa, you will either add an alkalinity increaser (like baking soda) if the levels are too low, or a pH decreaser (containing sodium bisulfate) if the levels are too high. Always retest your water after 24 hours to ensure proper adjustment.
Understanding Total Alkalinity (TA) in Your Spa
Total Alkalinity (TA) is a crucial measure of your spa water's ability to resist changes in pH. It acts as a buffer, preventing erratic pH fluctuations that can lead to various problems, including:
- Corrosion of spa components (low alkalinity)
- Scale buildup (high alkalinity)
- Ineffective sanitizers
- Uncomfortable water for bathers
Maintaining the correct TA level is essential for stable water chemistry and the longevity of your spa.
Ideal Total Alkalinity Range
For most spas and hot tubs, the ideal total alkalinity range is between 80 and 120 parts per million (ppm). Some sources may suggest a slightly wider range, but staying within this bracket is generally recommended for optimal water balance.
How to Test Your Spa's Alkalinity
Before making any adjustments, you must accurately test your spa water's total alkalinity. You can do this using:
- Test strips: Dip a strip into the water and compare the color changes to the chart provided.
- Liquid test kits: These kits involve adding drops of reagents to water samples and observing color changes. They often provide more precise readings.
Always follow the manufacturer's instructions for your specific test kit or strips.
How to Increase Alkalinity in Your Spa
If your test results show that your spa's total alkalinity is below the ideal range (e.g., below 80 ppm), you'll need to increase it.
When to Increase Alkalinity
Low alkalinity often leads to a phenomenon called "pH bounce," where the pH levels fluctuate wildly and are difficult to stabilize. You may also notice your sanitizer working less effectively.
Method: Adding an Alkalinity Increaser
The most common and effective way to raise total alkalinity is by adding baking soda (sodium bicarbonate) directly to your spa water. Many dedicated spa alkalinity increasers, such as SpaBoss Alka Rise, also use baking soda as their primary active ingredient.
Step-by-Step Guide:
- Calculate the amount: Refer to your alkalinity increaser product's instructions or a spa chemical calculator to determine how much baking soda you need to add based on your spa's volume and current alkalinity reading. A general rule of thumb is that 1.5 tablespoons of baking soda per 100 gallons of water will raise alkalinity by approximately 10 ppm.
- Turn off jets/air blowers: This helps prevent the chemical from becoming airborne and ensures better dissolution. Keep the circulation pump running.
- Dissolve the chemical: For best results, dissolve the measured amount of baking soda in a bucket of warm spa water before adding it to the spa. This prevents clumping and ensures even distribution.
- Add slowly: Pour the dissolved solution slowly into the spa water, preferably in front of a return jet to aid circulation.
- Circulate: Allow the spa to circulate for 30 minutes to an hour.
- Retest: Wait at least 24 hours before retesting your water to check the new alkalinity levels. Make further adjustments if necessary.
How to Decrease Alkalinity in Your Spa
If your test results indicate that your spa's total alkalinity is above the ideal range (e.g., above 120 ppm), you'll need to lower it.
When to Decrease Alkalinity
High alkalinity can cause the pH to be stubbornly high and difficult to lower. This can lead to issues like:
- Cloudy water
- Scale formation on the spa shell and equipment
- Reduced sanitizer effectiveness
- Skin and eye irritation
Method: Adding a pH Decreaser
To lower high total alkalinity, you typically use a pH decreaser, which often contains sodium bisulfate. Products like SpaBoss pH Minus are specifically designed for this purpose and will effectively reduce both pH and total alkalinity.
Step-by-Step Guide:
- Calculate the amount: Consult your pH decreaser product's instructions to determine the correct dosage based on your spa's volume and current alkalinity reading.
- Turn off jets/air blowers: Ensure the circulation pump is running.
- Dissolve the chemical (optional but recommended): Dissolving the granular pH decreaser in a bucket of warm spa water first can help prevent concentration in one area.
- Add slowly: Carefully pour the dissolved solution or granular product into the spa water, distributing it evenly across the surface or near the jets.
- Circulate: Allow the spa to circulate for 30 minutes to an hour.
- Retest: Wait at least 24 hours before retesting your water to check the new alkalinity and pH levels. You may need to repeat the process in smaller increments if the levels are still too high.
Summary of Alkalinity Adjustments
Here's a quick reference for adjusting your spa's total alkalinity:
| Condition | Action to Take | Common Chemicals Used |
|---|---|---|
| Low Alkalinity | Increase Total Alkalinity | Baking Soda (Sodium Bicarbonate), |
| (Raises pH slightly) | Alkalinity Increaser (e.g., SpaBoss Alka Rise) | |
| High Alkalinity | Decrease Total Alkalinity | pH Decreaser (Sodium Bisulfate), |
| (Lowers pH, which in turn lowers alkalinity) | pH Minus (e.g., SpaBoss pH Minus) |
Important Considerations and Tips
- Patience is Key: Adjusting water chemistry takes time. Always wait the recommended period (usually 24 hours) and retest before adding more chemicals. Over-treating can lead to new imbalances.
- Add Slowly and in Increments: Never dump large amounts of chemicals into your spa at once. Gradual adjustments are safer and more effective.
- Circulation is Crucial: Ensure your spa's pump is running when adding chemicals to help them dissolve and distribute evenly throughout the water.
- Interplay with pH: Total alkalinity and pH are closely related. Adjusting one will almost always affect the other. Often, correcting TA will help stabilize pH, but you may need to make separate pH adjustments afterward. For more details on pH, consult a guide on how to adjust spa pH.
- Read Product Labels: Always follow the specific instructions and safety warnings on your chemical products.
By consistently testing your water and making careful adjustments, you can maintain perfectly balanced alkalinity in your spa, ensuring a clean, safe, and enjoyable experience. For more comprehensive spa care tips, you can refer to resources like this spa water chemistry guide.
