CH concern in vinyl SWG pool?

[ePoolUser]

Hi,
I'm getting ready to convert to SWG. Reading the online manual for the Aqua Trol http://www.goldlinecontrols.com/Support ... 16G_SS.pdf it says you need a level of CH above 200ppm. They have a formula for "Saturation Index" that makes this CH level important. What about this with a vinyl pool? Currently my CH is 100 or less. Pool Calculator.com says I'll need to add about 20# of calcium chloride. Is this really a concern for a vinyl SWG pool?
Sorry to be dense, the manual says do it, but I gotta ask since it is contrary to most vinyl pool info.

Steve

 

[Guest]

get your CH to about 150 ppm and call it a day. With a vinyl pool you can run with a saturation index on the 'aggressive" side. It won't be a problem.

 

[Poolsean]

Waterbear,

Wouldn't you think there would be a problem if he had a copper heat exchanger heater? Back in the day when we still had cupricnickle heat exchangers in the Heat Wave Heat Pumps, we had many heat exchanger failures due to aggressive water. Mostly due to tab feeders plumbed before the heat pump, but none the less, some were contributed to poor water chemistry.

Just a thought

 

[Guest]

Waterbear,

Wouldn't you think there would be a problem if he had a copper heat exchanger heater? Back in the day when we still had cupricnickle heat exchangers in the Heat Wave Heat Pumps, we had many heat exchanger failures due to aggressive water. Mostly due to tab feeders plumbed before the heat pump, but none the less, some were contributed to poor water chemistry.

Just a thought

No, there is NO correlation between the saturation index and whether water is aggressive towards metals. (At least the LSI). It will predict scale formation but not corrosion. There other indicies that can predict corrosion to an extent but we don't use them with pools.