How Fix Green or Discolored Water
Green or discolored water is usually caused by algae growth or metals in the water.
- Algae can develop when sanitizer levels are too low and may appear green, yellow, black or pink
- Metals such as iron, copper, or manganese can cause water to turn green, blue, brown, yellow or black, especially when water chemistry is out of balance or after shocking the pool
A good clue is timing: if the water gradually turns green, algae is often the cause. If the water changes color suddenly after adding chlorine or filling the pool, metals may be the culprit.
Testing your water and maintaining proper sanitizer levels, pH and filtration can help prevent both algae and metal-related discoloration.
How to Fix Algae
- Keep the pump running
Run your pool pump 24 hours a day while treating algae. - Add an algaecide
We recommend FROG® Algae Gone® – a simple pod you drop in the skimmer for fast and effective results. - Shock the pool
After 24 hours, use a chlorine shock to raise the chlorine level to 3–5 ppm. - Balance the water
Keep Total Alkalinity between 80-120 ppm, pH between 7.2 and 7.8 and Total Hardness between 200-400 ppm. - Brush and vacuum daily
Clean pool surfaces at least twice a day to remove algae. - Clean the filter
After brushing or vacuuming, clean or backwash the filter to remove the dead algae. - Repeat as needed
Continue these steps until your water is clear.
How to Prevent Algae
- Maintain proper pH
Keep pH between 7.2 and 7.8 at all times. - Keep chlorine levels steady
Replace your Chlorine Pac regularly to maintain 0.5–1.0 ppm chlorine. - Check your equipment
Regularly inspect your pump, skimmer and filter for blockages. - Keep debris out
Remove leaves, bugs and other organic matter from the pool. - Shock regularly
Shock at least every other week and after heavy use or rain. - Avoid fertilizers nearby
Fertilizers can feed algae, so keep them away from your pool. - Use a preventative treatment
Add FROG® 90-Day Algae Barrier® for extra protection. - Lower your Phosphates
If your phosphate level is high use FROG® 90-Day Good-bye Phos®.


