Water hardness Climbing

[TRW]

I am confused, the pool CH is reading at 475 and seems to be climbing, the CH on the water source to the auto-fill when tested on its own is 100. Whats going on here, could the water be picking up Calcium from the pool?

TA-100
CC-0
FC-3.5
CH-475
PH-7.6
CYA-40

 

[PaulR]

When water evaporates, only the water evaporates. The calcium doesn't, it stays in the pool. Then the auto-fill kicks in and puts some water (with a bit more calcium) into the pool. So over time, the total amount of calcium will go up.

It is also possible that you're picking up some calcium from the plaster, especially if it's new (< 1 yr old), but the main culprit is the fill water.
--paulr

 

[TRW]

Hey Paul,
Thanks for the response, the pool is just a year old this month so that seems to be where the climb in CH is coming from. Do you think I should be concerned and do a partial drain/fill?
TRW

 

[duraleigh]

Do you think I should be concerned and do a partial drain/fill?

Probably not. Many pools function normally at CH levels higher than yours. If it were my pool, I would simply remind my self to keep pH and TA not higher than where they are right now.....7.6 and 100.

I would also remind myself to check all three of those parameters a little more frequently to make sure none of them get out of hand.

You should get some rainwater refill over the winter and far less evaporation so the CH may come back down on it's own.