After I opened up the pool I measured 0 FC. I have it 1.5 gal of 10% bleach and fc came up to 2.2 ppm. I added another half gallon and retested around 5:00 pm and it's back down to zero. I also added 2 gal of liquid stabilizer the day I opened (3 days ago) since there was almost no CyA. So my CyA is up to 35, pH is 7.3, TA=150, CH=470. How does CyA affect how much chlorine you need? The calculator says a gallon of 10% bleach should raise fc to 4.2. But I kind of doubt that. Pool is 24k gal. How much should I put in tonight. Big pool party tomorrow.
Chlorine all gone after 1 day
- Thread starter jdjohnsno
- Start date
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- Tags
- low free chlorine
Welcome to TFP!
4.2ppm is about right. Gallon of 10% will raise the FC of 10,000 gallons of water by about 10ppm. Multiply the water volume by 2.5 and that gives an increase of about 4ppm.
CYA reduces chlorine loss to sunlight.
A just opened pool will likely consume chlorine pretty fast as organic matter from the winter are consumed as well as the normal loss from sunlight, so your experience isn’t unusual.
Read the article on FC/CYA Levels for information on appropriate chlorine levels vs. CYA level.
4.2ppm is about right. Gallon of 10% will raise the FC of 10,000 gallons of water by about 10ppm. Multiply the water volume by 2.5 and that gives an increase of about 4ppm.
CYA reduces chlorine loss to sunlight.
A just opened pool will likely consume chlorine pretty fast as organic matter from the winter are consumed as well as the normal loss from sunlight, so your experience isn’t unusual.
Read the article on FC/CYA Levels for information on appropriate chlorine levels vs. CYA level.
- Jun 24, 2021
- 9,081
- Pool Size
- 30000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60
Do this test tonight. Could be you have algae, even if you don't see it. Link-->Overnight Chlorine Loss Test
I opened my pool and tested it and it measured 0 FC and 0 CyA. I put 1.5 gal of 10% bleach and the next day it measured 2.2 ppm FC. I also put in 2 gal of liquid CyA. The next day it measured 2.2 ppm fc and 30 ppm CyA. Then I added another gal of bleach. Next morning measuring 0 fc, cya still about 30. Last night added 3 gal of bleach. This morning 0 fc. Water seems to be getting greener. Please help me do the right thing. I'm tempted to go nuclear with the chlorine and throw 5 gal in there.
pH has stayed around 7.4. Volume is 24k gal. Thanks!
pH has stayed around 7.4. Volume is 24k gal. Thanks!
Deb04
LifeTime Supporter
- Jul 12, 2008
- 731
- Pool Size
- 19000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
You have algae and you need to SLAM. https://www.troublefreepool.com/blog/2018/12/12/slam-shock-level-and-maintain/
How are you testing your water. If you have one of the recommended test kits, you're all set to start your SLAM right now. Your pH is good, your CYA is good https://www.troublefreepool.com/blog/2019/01/18/test-kits-compared/
If you're using another test, test strips <pearl clutching>, or pool store testing <pearl clutching + gasp>, stop using that and order a recommended test kit. Add 1 gal + 1 quart of 10% liquid chlorine each day until the test kit arrives to stop the algae from getting worse. When your test kit arrives, do all the tests and report results. We'll help you from there.
How are you testing your water. If you have one of the recommended test kits, you're all set to start your SLAM right now. Your pH is good, your CYA is good https://www.troublefreepool.com/blog/2019/01/18/test-kits-compared/
If you're using another test, test strips <pearl clutching>, or pool store testing <pearl clutching + gasp>, stop using that and order a recommended test kit. Add 1 gal + 1 quart of 10% liquid chlorine each day until the test kit arrives to stop the algae from getting worse. When your test kit arrives, do all the tests and report results. We'll help you from there.