What is the correct chlorine ppm for a SWG pool?

[ned8377]

Hayward/Goldline has recommended 1.0 to 3.0 ppm chlorine levels. Pool math says the goal is 2 to 8 ppm.

 

[Propbndr]

What is your cya number?

 

[JoyfulNoise]

TFP recommends a 5% FC/CYA ratio for SWG pools and a minimum of 70ppm CYA to reduce SWG on time. So the absolute minimum FC value depends on where your CYA is at. I actually use 80ppm CYA due to intense sunlight and heat.

Ignore the industry guidelines as they do not recognize (or willfully ignore) the FC-CYA relationship. Their standard is 1-3ppm FC absolute and it is utterly wrong based on the science of cyanuric acid buffering of chlorine.

 

[Richard320]

1 to 3 is fine if your CYA level is zero. But there isn't a SWG made that can keep up with the UV losses if there's no CYA in an outdoor pool that gets a lot of sun. So the answer is to add some CYA and then adjust the FC level such that it never dips below the minimum.

What is your CYA level?

For a more in-depth and technical explanation of FC/CYA relationship, check Pool Water Chemistry

 

[swahl]

I have to chime in: The FC/CYA relationship is probably the most important thing I've learned from this Forum. I've not had an algae problem once since I found this website, and I believe it is because I now understand that item, and because I now treat my FC level as having a quite flexible (more of a guideline) maximum level, but an absolute minimum level.

Thanks to all of you!

 

[RobbieH]

http://www.troublefreepool.com/calc.html

 

[ned8377]

The Aqua Rite Operation and Installation Manual recommends CYA 60 to 80 with 80 being the best level. 5% of 60 is 3 ppm and 5% of 80 is 4 ppm. This corresponds with what is on the chlorine/cya chart for SWG pools in pool school. So what the Aqua Rite recommends is chlorine levels much lower than 5% of CYA. They must be assuming that people will be using algaecides etc because levels that low would definitely cause problems over time and are not recommended by the NSPF or TFP when CYA is 60 to 80 ppm.

I have a CYA of 60 ppm. On the Pool Math chart it says under Suggested FC Levels "SWG" 3 and then "Normal" 5 to 9. Is "normal" a non SWG pool?

Thanks.

 

[Richard320]

The Aqua Rite Operation and Installation Manual recommends CYA 60 to 80 with 80 being the best level. 5% of 60 is 3 ppm and 5% of 80 is 4 ppm. This corresponds with what is on the chlorine/cya chart for SWG pools in pool school. So what the Aqua Rite recommends is chlorine levels much lower than 5% of CYA. They must be assuming that people will be using algaecides etc because levels that low would definitely cause problems over time and are not recommended by the NSPF or TFP when CYA is 60 to 80 ppm.

I have a CYA of 60 ppm. On the Pool Math chart it says under Suggested FC Levels "SWG" 3 and then "Normal" 5 to 9. Is "normal" a non SWG pool?

Thanks.

Yes. Normal is us jug-dumpers.

 

[JoyfulNoise]

The Aqua Rite Operation and Installation Manual recommends CYA 60 to 80 with 80 being the best level. 5% of 60 is 3 ppm and 5% of 80 is 4 ppm. This corresponds with what is on the chlorine/cya chart for SWG pools in pool school. So what the Aqua Rite recommends is chlorine levels much lower than 5% of CYA. They must be assuming that people will be using algaecides etc because levels that low would definitely cause problems over time and are not recommended by the NSPF or TFP when CYA is 60 to 80 ppm.

I have a CYA of 60 ppm. On the Pool Math chart it says under Suggested FC Levels "SWG" 3 and then "Normal" 5 to 9. Is "normal" a non SWG pool?

Thanks.

An FC of 1-3ppm will work (sort of) in the lower CYA ranges. When you get to higher CYA ranges, 1-3ppm FC will be slower to kill algae and slower to oxidize bather waste. What will typically happen is a pool will become dull and possibly a little cloudy. So their assumption is that you will do what everyone does and take a sample to the pool store or have your pool service guy look at it. The recommendation will be to throw in a bag of shock (either dichlor or cal-hypo), fiddle with the TA (which is meaningless in this situation but gets you to buy some expensive baking soda) and add some clarifier or floc (again, useless except for draining your wallet). This will clear up the cloudiness (temporarily) and the SWG pool owner will be none-the-wiser. This process will repeat itself over and over and over again until the pool owner's water is so larded up with stabilizer or calcium or both that you will then be instructed to drain half your pool and start over again (but not before they've sold you a few bottles of PhosFree and algaecide first). The pool will eventually be closed (after a summer of on-again/off-again cloudy water) and the pool owner will just shrug it off as the plight of pool ownership...meanwhile, his neighbor, who is a TFP member and practitioner of the TFPC Method, will have both more swim days during the season than he AND more money in his wallet

As I said, simply ignore the 1-3ppm FC absolute recommendation as it is not grounded in anything remotely close to logic or science...

 

[ned8377]

Thanks everyone but especially Richard and JoyfulNoise.

 

[Sparkle]

Is your T-15 cell able to keep up with 45,000 gallons of water ?