Quck answer
Alum is a chemical compound commonly used in swimming pool maintenance. It helps to clarify pool water by removing impurities and particles. To use alum in your pool water, follow these steps:
1. Determine the correct dosage: Consult the manufacturer’s instructions or a professional for the recommended amount of alum based on your pool size.
2. Pre-dissolve the alum: Fill a bucket with water and slowly add the alum, stirring continuously until it dissolves completely.
3. Distribute evenly: Pour the dissolved alum mixture into the pool water, distributing it evenly across the surface.
4. Run the filtration system: Turn on the pool’s filtration system to circulate the water and help the alum work effectively.
5. Monitor and adjust: Regularly check the pool’s water clarity and adjust the alum dosage if necessary, following the manufacturer’s instructions.
Using alum in your pool can help maintain clear and sparkling water, enhancing your swimming experience.
Aluminum sulfate, also known as alum, can be a beneficial substance to utilize when the water in your swimming pool becomes cloudy or has a greenish tint. It functions as a “flocculant,” which attracts dirt particles, phosphates, pathogens, and other undesirable contaminants, causing them to clump together so that they can be easily removed from the pool through vacuuming. Alum was previously a common treatment for swimming pools until polymer pool clarifiers were introduced, but it is now making a comeback as a simple way to clear murky water.
Alum is available in powder form and can be found at any store that sells swimming pool supplies. You can mix the powder with water to create a slurry that can be added to the water, but the quickest and easiest method is to add it directly to the sand filter or to the surface of the pool.
Utilizing Alum in a Sand Filter
While alum should not be used in a DE (diatomaceous earth) or cartridge filter, it can be added directly into a sand filter because the clumped contaminants can be easily removed from the filter through backwashing and collected through vacuuming.
In order for alum to effectively clarify murky water, the pH level and chemistry of the water must be at the correct level. Therefore, the first step is to test and adjust the pH level and chemistry of the pool.
- Test the pool water and balance the chemistry to normal levels.
- Raise the chlorine levels to 10% of the cyanuric acid levels.
- Backwash the sand filter for an initial cleaning and take a pressure-gauge reading.
- With the filter running, pour 6 oz. of alum for every 100 lbs. of filter sand in the tank. Add the alum directly into the filter tank.
- Backwash the filter when the pressure rises 8 to 10 lbs. above the starting pressure. The pressure rise occurs because the contaminants have clumped together and are beginning to clog the filter.
- Vacuum the pool to collect the clumped contaminants (floc) that have escaped the filter. You should notice a significant improvement in the clarity of the water.
- Test the water chemistry again and make any necessary adjustments.
Using Alum on the Pool Surface
It is crucial that the pH and chemical levels of the pool water are correct in order for alum to effectively clarify the water. The first step is to test and adjust the chemistry of the water as needed.
- Remove large debris from the pool by skimming, vacuuming, and brushing.
- Check the pool water and adjust its pH and other chemical levels if necessary.
- Apply 4 lbs. of alum on the pool surface for every 10,000 gallons of pool capacity.
- Switch the filter pump’s multiport valve to “recirculate” and run the pump for two hours. This will cause contaminants to clump together due to the alum.
- While the water circulates, brush the sides and bottom of the pool to loosen any clumped particles.
- Turn off the pump for 12 to 24 hours, or until the clumped contaminants settle to the pool floor.
- Collect the settled contaminants by vacuuming the pool. Be careful not to vacuum too vigorously and break apart the clumped particles. You should notice a significant improvement in the water’s clarity.
- Check the water’s pH and chemistry again, and make any necessary adjustments.
