Back-Washing - Calcium Hardness not going down???

[LaROckl]

Newly re-plastered pool (plaster stripped to gunite) the pool was done about 10/12 weeks ago... then about 3 weeks ago ...Switched to Salt from FW.

Over the past three (3) weeks I've done some fairly heavy back-washing to bring the Cyanuric Acid level down... which it has done. We have enough rain here (New Orleans) that I almost *never* add city/tap water to the pool... i.e., all back-washing is co-ordinated with rainfall.

I'm still on a learning curve here... and, my question is: Salt (which, I've replenished) & Cyanuric Acid (now @ desired level) were reduced via back-washing but the Calcium Hardness has remained steady? What's up with that?

Thanks!

dennis

Pool Chemistry				New Sand Filter
				add Salt
	(Last Shock)	Heavy BW	BW	BW
Test Date	26-May	2-Jun​	8-Jun​	16-Jun​
Salt	3300	3100	3000	3300
	(3100)	(2900)	(2900)	(3200)
Free Chlorine	3.0	3.0	4.0	5.0
pH	7.2	7.6	7.4	7.6
Cyanuric Acid	100	85	80	75
Total Alkalinity	70	90	80	90
Calcium Hardness	280	280	280	280
Metals	0	0	0	0

 

[zea3]

As new plaster cures, pH and CH tend to go up. This process can take up to a year to stabilize. Just keep an eye on both levels and adjust as needed.

 

[LaROckl]

Thanks!!! makes sense... I'm adding about a gallon of Muriatic Acid per week to keep the pH in check. Guess I'll go get the parts and build an acid feeder today.

thanks again!!!!

dennis