I recently opened my in ground pool two weeks ago. The volume of the pool is approximately 20,000 gallons. The pool water has a greenish tint and the water appears cloudy. I have used a automatic robot to clean the bottom of the pool and clear out the debris settled down there. I have used a pool brush to scrub the walls / bottom of the pool in an effort to dislodge any debris. During all this time, the filter system was running on full. Chemistry of the pool as it stands right now:

  • PH of 7.6
  • total alkalinity of 90
  • Free chlorine of 2 ppm
  • combined chlorine of 3 ppm
  • Calcium hardness of 220

I have already shock chlorinated the pool two days ago. I added dry acid to lower PH from an initial reading 8.1 and calcium chloride to raise dissolved calcium levels from an initial level of 150 ppm. The pool is a concrete pool with no liner.

What could be causing the greenish tint to the water and the cloudiness of the water?

  • What did you shock with and with how much? My pool was green for a couple of weeks this year because we had very warm weather in early May which caused an algae bloom worse than I had ever seen before. Commented Jun 30, 2015 at 2:29
  • I generally need to shock our pool (50,000 litres) once or twice a year when it gets an attack of the greenies. I pour in a 20 litre container of sodium hypochlorite and wake up the next day to a clear pool.
    – rossmcm
    Commented Jun 30, 2015 at 4:06

2 Answers 2


Green is most likely algae, but it could be metals. You have to get your water tested for metals and phosphates (most pool stores will do this for free if you bring in a water sample), and then get rid of any measurable amounts using products designed for the purpose.

Cloudiness is also consistent with both of those problems, but could be independent: If after you resolve any algae and/or metal problem it's still cloudy then add a clarifier. If that doesn't solve cloudiness then you would most likely have a filter problem – e.g., tear or leak in the filter.


I had the hardest time with this until I realized I needed to get a new filter. I also had to clean the filter every day for a couple days to get the caught algae out of the system.

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