Confused about recommended CH level for SWG in fibreglass

[dave0706]

Hi TFP members,

I’m a little confused as to what I should aim for with CH in my fibreglass swg pool.
If I select SWG and Fibreglass at TFP’s ‘What Are My Ideal Pool Levels?’ article, it says ideal CH range should be 350-550ppm.
(Link: What Are My Ideal Pool Levels?)

However, the post titled ‘Water Balance for SWGs’ lists two different ranges for fibreglass pools. In the main body of the article it says ‘Adjust Calcium Hardness to 350 ppm for plaster and fiberglass’, however in the summary under ‘To summarize’ the same article says maintain a CH of 220-320 for fibreglass.
(Water Balance for SWGs)

Currently my CH is 275ppm, and I don’t want to overshoot up to 350-550 if it should be less.

Any advice would be greatly received. I’m sure I must be missing something.

Thanks
Dave

 

[PoolStored]

Currently my CH is 275ppm, and I don’t want to overshoot up to 350-550 if it should be less.

Older FB pools had calcium in the production process and the CH recommendations were to protect them. Now, the main reason is really for stain prevention, since today's FG pools should not have any calcium added during fabrication. Plus, statistics from across the TFP population showed that 250 was a reasonable minimum number for all to achieve. Still, some FG owners choose not to increase it to 250, and if you chose to err on the side of caution and not add enough calcium to make it to 250, that's certainly your call.

275 is fine.

 

[dave0706]

Older FB pools had calcium in the production process and the CH recommendations were to protect them. Now, the main reason is really for stain prevention, since today's FG pools should not have any calcium added during fabrication. Plus, statistics from across the TFP population showed that 250 was a reasonable minimum number for all to achieve. Still, some FG owners choose not to increase it to 250, and if you chose to err on the side of caution and not add enough calcium to make it to 250, that's certainly your call.

275 is fine.

Thank you very much

 

[Mdragger88]

What is the ch of your fill water?
That needs to be taken into consideration too as it can cause your ch to increase over time.
A Lower ch doesn’t really harm anything but high ch can cause scaling on surfaces & equipment.

 

[Newdude]

*exception to the 'modern fiberglass doesn't need calcium' train of thought is when there are waterline tiles / grout.