Calcium Hardness Constantly Decreasing! Why?

[dino1956]

I have a Gunite Pool. 28,000 Gallons. 20'x40'
A little over a month ago I tested for CH & it was Low at 180. So I added 33 LBs of Calcium Chloride & that brought it up to 300. Now a little over a month later I tested again & it's back down to 180.
I know how important Calcium is to a Plaster Pool. I have 2 small spots the size of a nickel where it looks like Plaster might have been eaten away.
Yes, there has been rain here. But I don't think enough to lower that much. Why is my Pool constantly needing & eating up Calcium Chloride?

Test Results:
PH: 7.6
TA: 80
CH: 180 ???
CYA 60

Thanks in advance!

 

[RobbieH]

The only way I know of to have falling CH is a leak in the pool. Do you have to fill a lot?

 

[duraleigh]

Confirming what robbieH says, CH never leaves your pool unless you are replacing the existing water with new water lower in CH.

 

[dino1956]

Yes, I do have some Leaks in Tile. About an Inch every 3 days. Is that considered a big leak?
Thanks for the quick replies. That makes Total Sense. I did not think of that!

I guess the leak has helped in another way though. My CYA needed to come down & it to is almost close to where it should be.

 

[Richard320]

Yes, I do have some Leaks in Tile. About an Inch every 3 days. Is that considered a big leak?
Thanks for the quick replies. That makes Total Sense. I did not think of that!

Let's see... with you dimensions and volume, your average depth is about 56". 3" is 5% of that.

So you will lose about 5% CH every week. 5% CYA, too.....

 

[RobbieH]

That size leak for me adds up to a BUNCH of water to replace. You can fix it yourself if you know where the leak is with epoxy putty. If you don't, I highly recommend American Leak Detection if they are in your area. They will charge you less if you know for sure there are no leaks in your plumbing, as they won't have to do all those tests. If you aren't sure, it might be worth the investment to let them go for it.

 

[dino1956]

Richard, Thanks for the calculation!
Yea Robbie, I'm running my Hose for 2-3 hours a week to compensate. I need to get this fixed.
I don't really have any reason to be believe it's my Plumbing. There are like 5 Tiles with visible Gaps in them.
I have a company in my area. And I just looked there is America Leak Detection in my area. Thank you both for the Info.

 

[RobbieH]

A lot of the pool companies simply send ALD if you call them. Might as well go straight to the source.

 

[dino1956]

But will these guys fix leaks? Do they Install Pool Tiles, grout, etc...?