will low CH help calcium scaling

[anuoldman]

will low CH help calcium scaling... I've got classic calcium scaling, greyish tint that only shows up in certain light but was obvious with the pool drained....

I just refilled and have extra low CH, will leaving that low for a while eat the scaling or the plaster first?

 

[JasonLion]

Keeping CSI quite low, not just CH, will dissolve calcium scale off the walls. It will also, to some extent, attack any exposed plaster. Generally it removes scale first, but that is never completely true.

This is called a no-drain acid wash and is done by lowering CSI to around -1.2 to -1.0 and keeping it there. CSI can be calculated with the Pool Calculator. It depends on several factors, but most prominently on PH, TA, and CH. As calcium dissolves, it will raise PH, TA, and CH back up, so you need to monitor all three levels and keep them low.

Doing a full drain acid wash is far more work, but it gives you control over exactly what gets removed, at least if the person doing it is sufficiently skilled.

 

[anuoldman]

thanks!