Aluminum Sulfate

• Aluminum sulfate is used in swimming pools to eliminate phosphate levels in a pool. Phosphates present in a pool will cause algae to grow, because phosphates are one of the largest sources of food for the algae plants. Using aluminum sulfate to remove phosphates is a fairly simple process, but it does take time. Purchase some aluminum sulfate conditioning powder or liquid. You will need 5 lbs. per 10,000 gallons in your pool. Add the sulfate to the pool and use the recirculation setting on your pool filter for three hours. Once this has finished, allow the water to settle for 36 hours. Vacuum the bottom of the pool to remove the sulfate powder and algae. Rebalance the pool by adding chlorine or water to return the pH levels in the pool to around 7.4. You may need to follow this process with additional phosphate removers.
  
  

Copper Sulfate

• Copper sulfate is another chemical mixture used to reduce algae. However, the copper present in the solution can cause dying of the pool, swimming suits and hair. Many pool manufacturers do not recommend the use of copper sulfate in swimming pools. However, there are some solutions that are designed for pools if used properly. Add crystals to the pool following the package directions for the size of your pool. Recirculation is a necessity after the application of the sulfate to prevent staining on the pool walls and swimsuits of swimmers. Using a copper sulfate system also reduces the amount of chlorine that must be added to the pool.
  
  

Sodium Bisulfate

• If the pH levels in the pool become too high, sodium bisulfate can be added to lower the pH. The ideal pH range for a swimming pool is around 7.4 Other algae sulfates cannot be added while the pH is too high, so keeping the pH at a lower level is important. Scatter the granules across the pool surface and allow them to dissolve. One pound of sodium bisulfate per 10,000 gallons will lower the pH of the pool .04 points. Allow the crystals to sit in the pool for 24 hours before retesting the water to check the new pH level.