Quick Answers
There are a few options to make your pool water look bluer, such as using a blue dye or installing a mineral sanitizer system. Keeping the water clean and balanced is also key to achieving that bright blue color.
What Makes Pool Water Blue?
The bluer and more vibrant a swimming pool looks, the healthier the water is. When properly balanced and sanitized, the water molecules scatter blue wavelengths of light, making the water appear blue. Particles like dirt, debris, and algae can cause your pool water to look green or cloudy instead of blue. Additionally, imbalanced water chemistry can affect the water color.
The Impact of pH on Pool Water Color
The pH level has a big effect on the perceived color of pool water. Properly balanced pool water should have a pH between 7.4-7.6. At this level, the water will strongly scatter blue light waves, making it look bright blue. If the pH creeps above 7.8, the water will start to look greenish or murky. Below 7.2 pH, the water appears cloudy and dull.
Chlorine’s Effect on Pool Water Color
Chlorine is vital for disinfecting pool water and preventing algae growth. But chlorine alone will not make your water blue if the pH is off. Additionally, too much chlorine can start to make the water appear greenish. Between 1-3 ppm is ideal for residential pools. Shocking the pool regularly will oxidize contaminants that dull the water.
Total Alkalinity and Water Color
Total alkalinity acts as a buffer to prevent pH fluctuations. Levels between 80-120 ppm are recommended. If total alkalinity drops too low, the pH will be harder to adjust and maintain. Without this buffering capability, pH changes can allow the water to appear green or cloudy.
Calcium Hardness and Pool Clarity
Having adequate calcium hardness between 200-400 ppm will help the water stay clear and blue. Calcium helps prevent corrosive water conditions that degrade the plaster surfaces. If calcium is too low, plaster damage can allow staining and cloudiness to occur.
Perform Regular Maintenance
Consistent pool maintenance is crucial for water clarity and blueness. Here are some tips:
- Test and adjust chlorine, pH and alkalinity weekly.
- Shock the pool regularly to oxidize contaminants.
- Brush walls and bottom manually or with an automatic pool cleaner.
- Check and clean filters regularly.
- Use clarifier or flocculant if water appears cloudy.
- Watch for algae growth and treat immediately if needed.
Methods to Make Pool Water Bluer
If your water is properly balanced but still not as blue as you’d like, try these tricks:
Add a Blue Dye or Colorant
Blue dye contains concentrated color pigments that tint the water. Results are immediate, but dyes gradually fade over time. Follow label directions carefully, as using too much can make the water overly dark.
Install a Mineral Sanitizer System
Mineral sanitizers use metals like silver, copper and zinc instead of chlorine to disinfect the water. The metals give the water a bright aqua glow when dissolved. These systems are low maintenance but higher cost.
Switch to a Biguanide Treatment System
Biguanide (also called PHMB) is a non-chlorine sanitizer. It provides a sparkling blue tone when used as the primary sanitizer. Biguanide is paired with an oxidizer for maximum effectiveness and blue color. Drawbacks are higher costs, more difficult maintenance and potential related health issues.
Use a Stain and Scale Control Product
Stain and scale inhibitors prevent metals that discolor the water from depositing on pool surfaces. By binding to the metals, these sequestering agents allow them to be filtered out. This prevents dull, greenish water and stains.
Common Causes of Green Pool Water
If your pool water is green or has a greenish tint, one or more of these factors is likely the cause:
Improper pH Balance
A low pH below 7.2 allows green-colored copper ions to dissolve into the water. Raise the pH to bring it into the ideal range between 7.4-7.6.
Low Chlorine Level
Without adequate disinfection between 1-3 ppm, algae can grow, turning the water green. Shock the pool and raise the chlorine level.
Low Total Alkalinity
Alkalinity below 80 ppm makes pH control difficult. Fluctuations in pH allow green copper ions to enter the water. Raise alkalinity to between 80-120 ppm.
High Nitrate Levels
Nitrates can build up from chlorine use, fertilizers, runoff and other contaminants. High levels allow algae to thrive. Keep nitrates below 30 ppm.
High Iron or Copper Content
Dissolved iron or copper from piping, fittings and source water causes greenish staining. Use a sequestering agent to bind the metals so they can be removed through filtration.
Algae Growth
If green algae is visible in the water or growing on surfaces, it will impart a green color. Shock and brush the pool, then maintain proper sanitizer levels to prevent recurrence.
How to Get Rid of Green Pool Water
Here are the steps to restore blue water if your pool has turned green:
- Test and balance pH between 7.4-7.6.
- Shock the water with chlorine or other oxidizing shock.
- Brush walls and floor thoroughly.
- Run filter 24 hours per day until water clears.
- Use flocculent to clump algae and debris for removal.
- Vacuum water through waste setting to remove clumps.
- Continue adding chlorine to maintain 1-3 ppm.
- Check other water balance levels and adjust as needed.
- Add algaecide if needed to prevent regrowth.
With consistent maintenance to prevent future algae growth, your water should return to a sparkling blue!
How Long Does It Take to Clear Up Green Pool Water?
It usually takes 3-5 days to clear green pool water using the process above. Very severe algae blooms could take up to 2 weeks to get the water fully blue again. Be patient and continue efforts until all evidence of green is gone. Once clear, stay vigilant in your chlorine and maintenance routines.
Preventing Green Water in the Future
Here are some tips to keep your water blue and prevent green algae problems:
- Maintain 1-3 ppm chlorine at all times.
- Test and adjust pH, alkalinity and calcium hardness weekly.
- Shock weekly or as needed to oxidize contaminants.
- Run filter and clean regularly according to manufacturer.
- Brush walls and bottom manually or with automated cleaner.
- Monitor CYA level and drain/dilute if over 70 ppm.
- Quickly treat any signs of algae with algaecide.
- Frequently skim water surface.
Staying on top of these maintenance items is the best way to achieve clear blue water.
Safe Use of Blue Pool Dye
While blue dye can enhance the pool’s color, use these tips for safety:
- Only use dyes labeled for pool use.
- Follow label directions carefully to avoid overdosing.
- Start with half the recommended dose to gauge color.
- Add more in 24 hours if needed for desired color.
- Spread dye evenly around the perimeter before running the pump.
- Test regularly as dye can dilute chlorine levels.
- Shock as needed if chlorine drops below 1 ppm.
- Avoid getting dye on pool surfaces as it can stain.
Remember that dye is just cosmetic and won’t fix underlying water quality issues. Proper pool maintenance is still required.
Using a Reflective Pool Bottom for Bluer Water
The pool floor material and pattern impacts how the water absorbs light. Here are some tips:
- Light colors like white plaster reflect light, enhancing the blue.
- Dark floors absorb more light, making the water appear darker.
- Sizing pool floor aggregates for exposed plaster also affects color.
- Glass/tile floors in custom colors reflect varying amounts of light.
- Printed plaster designs can mimic the look of tile at a lower cost.
Discuss floor color and finish options with your pool builder if planning a new installation or plaster redo.
Should I Empty and Refill My Green Pool?
In most cases, draining and refilling the pool is unnecessary to clear up green water. It’s time consuming and wastes water. Follow these steps instead:
- Test and balance all water chemistry levels.
- Shock and brush the pool thoroughly.
- Run filter 24 hours until water clears.
- Vacuum any debris on waste setting.
- Maintain proper chlorine levels.
For severe long-term algae problems, draining may be needed if clearing attempts fail. But try other methods first.
When to Call a Pool Professional for Help
It’s wise to contact a pool pro if you experience any of the following:
- Green water that won’t clear after multiple attempts.
- Difficulty balancing water chemistry levels.
- Problems identifying and resolving an issue.
- Frequent algae blooms.
- Stains or scaling on pool surfaces.
- Cloudy water even after shocking and filtering.
- Any sign of an equipment malfunction.
Pool service pros have specialized knowledge, tools and supplies for diagnosing and resolving water clarity issues. They can get your pool blue faster and suggest enhancements.
Frequently Asked Questions
Here are answers to some common pool blueness questions:
Will using salt chlorine make my pool bluer?
Maybe. Salt chlorine systems produce pure chlorine on site, avoiding contaminants from store bought products. This can enhance water clarity. But salt systems won’t fix underlying issues making water green.
Will a UV system make my pool bluer?
UV light destroys pathogens and some algae that rob water of blue tones. But UV alone won’t balance chemistry or fully get rid of green algae blooms.
Should I change my old white-colored filter sand?
Yes, opting for new blue glass media will provide better filtration. Old sand also harbors debris and chemicals that dull water color.
Will replacing my plaster make my pool bluer?
A fresh plaster surface is very reflective and will make blue tones pop. Address existing water issues first so new plaster stays blue.
What chlorine level is best for blue pool water?
1-3 ppm chlorine will prevent algae growth while safeguarding water color. Too low encourages algae, while too high can make water appear greenish.
Conclusion
Achieving bright, vibrant pool water requires vigilance in monitoring and maintaining proper water balance and sanitation. While dyes and enhancements can help, fixing underlying issues is key to sustainable color improvement. With consistent testing and maintenance to control pH, sanitizer levels, circulation and contaminants, your pool water will shine blue all season long.
