CYA and FC levels with SWG

[mizzouguy]

Why is it that most posts I see people posting 60-80 cya levels and only 2-3ppm FC levels? When I look at Ben's best guess it should be 5-10.

I did the same thing all last year and didn't have any problem, but this one has always confused me. I know it's called best guess, but why don't I see more people with levels that match up? (Maybe I just notice them more....)

Do the SWG allow lower FC levels or am I missing something?

(33k gal, vinyl, Aquarite)

[gwrace1]

If you read the owners guide for an Aquarite SWG they want you to run 80PPM on the stabilizer.

With our 26K gallon round pool I run 40PPM stabilizer and maintain 3.5 PPM FC. The water is crystal clear and I've never had an algea problem.

I run the pump on low speed for 12 hours per night with the SWG set on 40-50 %. All readings are taken with a Taylor test kit during the middle of the day with pump off.

[mizzouguy]

Another example....you run at 3, but the chart says you should be at 5 minimum, correct???

I agree it works perfect, I just don't quite get the chart!!!!

[aylad]

The chart says 3-6 ppm for a CYA of 40. And the chart isn't an absolute, it's a guideline...

Janet

[waste]

Hi all. I had a big issue with Goldline (now Hayward) when we first started installing their units a few years back, about the higher cya level. There is apparently nothing inherent in the SWG which would require twice as much cya as a pool chlorinated in other ways. However, they all seem to call for a higher cya level. (Actually, after a few 'heated' discussions, I'm supprised they still answer my calls )
As I see it; salt will only leave the pool by backwashing or splashout. Similarly, cya isn't going anywhere the salt doesn't go (niether will evaporate with the water). Therefore, I present "Waste's Best Guess Chart For CYA in a SWG Pool":
*** For every 100 lbs salt added, add 1 lb cya***
This will get you 30-40 ppm cya ( for systems that opperate on a 2600 - 3400 ppm salinity) Keep your cl ~ 2.5 - 3 and you should not experience problems!