How do you use alum salt in a swimming pool?

Using alum (aluminum sulfate) in swimming pools is a common practice to address cloudiness caused by high levels of suspended particles or colloids. Alum works by forming larger particles from the smaller ones, making it easier for the pool filter to trap and remove them. Here’s a comprehensive guide on how to use alum in swimming pools:

1. Test Water Quality:

Before adding alum to your swimming pool, it’s essential to test the water quality using a reliable pool water testing kit. Check the pH, alkalinity, and chlorine levels to ensure they are within the recommended ranges.

2. Determine Alum Dosage:

The dosage of alum depends on the size of your pool and the severity of cloudiness. Typically, you will find recommended dosage instructions on the alum packaging. Follow these guidelines or consult with a pool professional to determine the appropriate amount for your specific situation.

3. Pre-dissolve Alum:

Alum is best added to the pool after it has been pre-dissolved. This helps prevent the alum from clumping or settling at the bottom of the pool. Dissolve the recommended amount of alum in a bucket of water, stirring thoroughly until it completely dissolves.

4. Broadcasting Alum:

Once the alum is dissolved, broadcast it evenly across the surface of the pool. It’s advisable to pour it around the perimeter to ensure even distribution. Use a pool brush or a pool broom to help disperse the alum more uniformly.

5. Run the Pool Pump and Filter:

After adding alum, run the pool pump and filter continuously for at least 24 hours. This helps in circulating the water and allows the alum to effectively coagulate and settle the particles. Check the pressure gauge on your filter system to monitor any changes.

6. Monitor Water Clarity:

Regularly check the water clarity during the process. If the pool remains cloudy after 24 hours, you may need to add more alum. However, it’s crucial not to overdose, as excessive alum can lead to issues like low pH or aluminum scaling.

7. Backwash the Filter:

Once the alum has had time to work, backwash the pool filter to remove the collected particles. This helps maintain the efficiency of the filter and ensures that the water circulation is not hindered.

8. Retest Water Chemistry:

After a few days, retest the water chemistry to ensure that the addition of alum has not significantly affected the pH, alkalinity, or chlorine levels. Adjust the chemical balance if necessary.

9. Preventative Measures:

To prevent future cloudiness, maintain proper water chemistry, and regularly clean the pool. Consider using a pool clarifier or flocculant as part of your routine maintenance to enhance water clarity.

10. Consult a Professional:

If you are unsure about the dosage or the process, it’s always wise to consult with a pool professional. They can provide personalized advice based on your specific pool conditions.

By following these steps, you can effectively use alum to clarify your swimming pool water, ensuring a clean and inviting swimming environment.