Why 4-6 ppm FC for SWG?

[Neworldjef]

Hi All,

Been part of TFP for years and have a good degree of mastery of chemistry. I'm wondering the rationale for recommending 4-6 ppm for a pool with SWG? It definitely seems to take color out of my liner quicker than when I kept levels of FC at 1-3 ppm. Wondering the reasoning so I can decide with my new liner (next season) how high I want to keep it.

Thanks!

Jeff

 

[mknauss]

Based on CYA level. Target is essentially 7.5% of CYA. Minimum is 5% of CYA.

Liner should not be effected at levels below SLAM level.

 

[ajw22]

Read about level of active chlorine HOCL with CYA in CYA Chlorine Relationship - Further Reading

 

[PoolStored]

There is no recommendation here to keep FC 4-6 (except in chart I'll link). There are recommendations to keep FC at particular levels depending on your CYA level. See here: FC/CYA Levels

There are also lots of threads on the correct CYA level for an SWG Pool: High CYA with SWG.

 

[Neworldjef]

There is no recommendation here to keep FC 4-6 (except in chart I'll link). There are recommendations to keep FC at particular levels depending on your CYA level. See here: FC/CYA Levels

There are also lots of threads on the correct CYA level for an SWG Pool: High CYA with SWG.

See here for suggestion of 4-6 for SWG - Water Balance for SWGs - Trouble Free Pool

 

[JJ_Tex]

Yes, and it also recommends keeping your CYA at 70-80 and even states:
Second adjust CYA to between 70 and 80. The biggest mistake that many SWG owners make is NOT having enough CYA in the water!

What is your CYA level?

Regardless, FC should be proportionate to your CYA. If the ratio is too high or too low, you can have issues.

 

[JoeSelf]

I read here a while ago that the newer liners need higher than minimum calcium levels or colors fade quicker, affects blue more.

 

[mknauss]

I read here a while ago that the newer liners need higher than minimum calcium levels or colors fade quicker, affects blue more.

Older liners. The newer vinyls do not require the same level of CH nor use the pigment that fades.

 

[Neworldjef]

Yes, and it also recommends keeping your CYA at 70-80 and even states:
Second adjust CYA to between 70 and 80. The biggest mistake that many SWG owners make is NOT having enough CYA in the water!

What is your CYA level?

Regardless, FC should be proportionate to your CYA. If the ratio is too high or too low, you can have issues.

Keep my CYA in that range. Just wondering about the liner fade most of all. Seems from what others write here. older liners used pigment that would fade. Maybe that is all. Although my previous liner of 12 years did not fade this quickly and my current liner is when i started SWG and FC 4-6...

 

[TexEdmond]

Although my previous liner of 12 years did not fade this quickly and my current liner is when i started SWG and FC 4-6...

Who can forget the immortal words of the late, great Merle Haggard?

"I wish a Ford and a Chevy (and a pool liner) would still last 10 years like they should... Is the best of the Free Life behind us now, and are the good times really over for good?"

 

[borjis]

You might check for iron in your water.
Light staining can make the liner look faded.
My liner is much less blue than it used to be.
An ascorbic acid treatment returned the blue. I'd literally forgotten just how blue it was.