Why does Intex recommended 20-40 cya for SWG

cfclay

Well-known member
Apr 24, 2010
233
Lexington,Ky
Sorry if this has been asked before...just noticed Intex recommends 20-ppm for CYA for Model 7110 and 8110 Salwater System. Wonder why? TFP recommends 70-80 right?
 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
10,395
Franklin, NC
For the same reason they show a maximum of 5 FC. The pool industry refuses to recognize the connection between CYA/Stabilizer and the ability of chlorine to do it's thing sanitizing the water. Others here can give you the scientific details if you want, but lets just say CYA locks the ability of chlorine to sanitize. The more CYA you have the more chlorine you need to keep in the pool to keep algae at bay. I took over my pool with a CYA of about 250 (CYA tests above 100 are just a guess, not very specific contrary to what the pool store says). With a CYA of 250 I had to keep my chlorine level at around 20 just to keep algae away.
 

cfclay

Well-known member
Apr 24, 2010
233
Lexington,Ky
For the same reason they show a maximum of 5 FC. The pool industry refuses to recognize the connection between CYA/Stabilizer and the ability of chlorine to do it's thing sanitizing the water. Others here can give you the scientific details if you want, but lets just say CYA locks the ability of chlorine to sanitize. The more CYA you have the more chlorine you need to keep in the pool to keep algae at bay. I took over my pool with a CYA of about 250 (CYA tests above 100 are just a guess, not very specific contrary to what the pool store says). With a CYA of 250 I had to keep my chlorine level at around 20 just to keep algae away.
Thanks for the response! I don't follow you though.
Intex is recommending a lower CYA. It sounds like you might be asserting the industry wants you to have a higher CYA to sell you more chlorine?
 

BasicTek

Bronze Supporter
Oct 9, 2016
867
Lake Mary, FL
Other than the basic poor information propagated by the pool industry it's possible that they want you to have to run your SWG more, so it gets used up faster, and then you need to by a replacement sooner, which is more $$$ for them.... just a thought...
 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
10,395
Franklin, NC
Thanks for the response! I don't follow you though.
Intex is recommending a lower CYA. It sounds like you might be asserting the industry wants you to have a higher CYA to sell you more chlorine?
The main thing is that their recommendations never change. TFP follows the science and the industry keeps parroting what everyone before them has said.
 

PoolguyinCT

In The Industry
Jul 21, 2014
3,083
Connecticut
The main thing is that their recommendations never change. TFP follows the science and the industry keeps parroting what everyone before them has said.
When CDC & various health regulations change, industry recommendations will change.

In practice, the contractor segment of industry has long been aware of the CYA - chlorine synergy..

No entity / manufacture will publish recommendations that do not sync with state or fed - cdc, health etc..

When the fed changes its recommendations, private industry will publish likewise.
 

Donldson

TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
3,945
NW Ohio
What Poolguy said. These numbers aren't something that the people at Intex sat down and figured out. They copied them from the standards set by the industry. No additional thought went in to them, Intex isn't recommending anything, they are just reprinting a chart. Same as every manufacturer in the industry.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,260
Tucson, AZ
The industry is currently putting a maximum FC at 5 PPM in order for that to keep in the pool relatively clear one must keep a lower cya. Our recommendations for a higher cya better protect the chlorine from the Sun and allow your swg to not have to work as hard.