Increasing Calcium Hardness

I just went to the pool store to triple check myself on all my levels..it was just for peace of mind and also I was itching to be "perfect pool water of the month" member lol :-/

I was so confident in my pristine water from what I have learned on this board (i want to support more and hope to upgrade to the higher subscription soon!!). So they ran the test and actually said my water was near perfect - yay!! But that there was maybe one SMALL thing I could do because my calcium was low. I was caught off guard, as I had not read anything on calcium here, i guess I was just never looking for it!! She even said "well its not 10000% necessary but it COULD help your pool last longer and it won't hurt"...so I ended up buying the calcium for $30 then came home and immediately came to the pool forum and low and behold read all the info on not needing it for vinyl liner pools!! My hardness was at 73 and it was suggested that it be at 125-140. So after reading this board I did not want to use it and I sent my husband to return it. Unfortunately you apparently cannot return pool chemicals darn it! Then they told him that we really should just use it because even though 73 is not low, if it gets down to 20-30 it will start looking for calcium from the concrete behind the liner. So...yes we do have concrete behind the liner I think, does this make a difference?

I just read on here that if it gets too high it can cause calcuim build up. We have hard water as it is in our water well which we use to fill our pool when it gets low so I can't imagine it ever getting real low but maybe it will.

They are giving you a line that, with a little close reasoning, will reveal it.

How will water get behind your liner?
Either your liner is torn and is leaking, or it is ground water.
If it is torn and leaking enough long enough to erode your concrete, you have far bigger problems than calcium deficiency.
If your liner is for a steel in-ground structure, or uses a sand base, calcium is again irrelevant, and you have bigger problems from the leakage.
If the water is ground water, the calcium in the pool water won't affect it either.

Give the. calcium to a friend with a concrete, plaster, or other hard-sided pool.

A pool store that will not take back a sealed chemical probably should not get your business, especially if they cook up a crock the way they did.

Thank you Carl! It won't get behind the liner...for some reason the first thing that came to mind was reading something on here about the liner having little particles of something (calcium?) built into it that it would draw out (very rare). Sounds crazy to me...off to find a friend who has a concrete pool to give this stuff to :-) Thanks again!

The liners are frequently made from whatever sheet vinyl in the right thickness the manufacturer can find. There is SOME discussion that some may have calcium in them but we have never seen a case of a vinyl liner deteriorating because of too little calciium in the water.