green pool

  • Last Post 19 August 2019
  • Topic Is Solved
Page72 posted this 15 August 2019

This summer I have been fighting a green pool. Currently my chlorine is @ 13 for free chlorine, my ph is 7.4, alkilinity is 120, CYA is 150. 

First there were only small amounts of green on the pool floor, then the pump motor went out and it was 3 days before i got it back up and running, now completely green and cant get it to clear up. Tried shocking it and using algae 60, brushed all walls and floor of pool, and running on filter for 48 hours with no change. I was told I probably have mustard algae so I added algae all and brushed again and still running filter now running 48+ hours with no change. What do you suggest?

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InyoRob posted this 15 August 2019

Your CYA is very high at 150. The free chlorine becomes less effective when the CYA is that high. My suggestion would be to get that CYA level down in the 50 ppm range. In order to do that you have to drain some pool water and fill with fresh water.

Once you lower the CYA level, continue to chock the pool and clean the filter. The filter may need to be cleaned several times a day until the water clears up.

Page72 posted this 15 August 2019

Can you give me a link to find the calculator for lowering my CYA?

Page72 posted this 15 August 2019

InyoRob posted this 15 August 2019

This is a good calculator.

Walter145302 posted this 19 August 2019

I was fighting a similar problem. While not as geeen as your pool I could not get the green to clear up. I brushed and shocked the pool and used green to clean. Finally the pool people suggested that I use liquid chlorine and super shock the pool. My pool is just under 10000 gallons and she gave me 7 gallons of liquid chlorine. Within just a few hours the pool started to clear up and by the next day it was crystal clean. Have not had a problem since. Good luck!

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Page72 posted this 19 August 2019

I drained the pool down to just a foot in the shallow end, refilled the pool all was clear and shocked with liquid chlorine now back to green and my chlorine is @15 and  CYA is now 113, WTF?????


Page72 posted this 19 August 2019

how much water do i need to drain to get my CYA down?

Page72 posted this 19 August 2019

18' x 36'

depth: 4 foot area 12ft then slopes down to 9 foot in the deep