Calcium Hardness

[skyfly27]

Can someone tell me why calcium hardness is important for a gunite pool? I measured mine at 150. The pool math calculator says I need to add 25 lbs of calcium chloride. Just wondering why this is necessary?

 

[Texas Splash]

When the CH level gets too low in a a plaster pool, the water is starved for calcium and looks for a place to grab it - the pool shell. Over time that can result in plaster etching and damage. For that reason, it's important to have the minimum amount required. By contrast, if you had too much calcium and it over-saturates the water, it looks for a place to stick - scale.

Pool Care Basics Archives

Your one-stop shop for all things TFP to include: ABCs of Water Chemistry, Recommended Chemicals/Levels, Test Kits, Troubleshooting, and much more!

www.troublefreepool.com

 

[skyfly27]

When the CH level gets too low in a a plaster pool, the water is starved for calcium and looks for a place to grab it - the pool shell. Over time that can result in plaster etching and damage. For that reason, it's important to have the minimum amount required. By contrast, if you had too much calcium and it over-saturates the water, it looks for a place to stick - scale.

Pool Care Basics Archives

Your one-stop shop for all things TFP to include: ABCs of Water Chemistry, Recommended Chemicals/Levels, Test Kits, Troubleshooting, and much more!

www.troublefreepool.com

Thank you! Is there a more specific range? I am seeing 350-550

 

[Texas Splash]

350-550 is about it, The range for CH gives owners plenty of flexibility to keep the plaster safe while preventing scale. Keep in mind a lot has to do the 3 other factors: water temp, TA, and pH ... pH having the biggest influence. But if you keep all your numbers within those recommended ranges, you'll be fine. Plus, the PoolMath APP will let you know if any area should be addressed, so if you have a questions if that happens just let us know.