What causes Calcium to rise?

[SoCalBoo]

I realise that Calcium is usually present in fill water. Our fill water is about 190-200. I understand that as water evaporates and new water fills, calcium will increase.

But our pool was filled last August. My calcium level is 430. Assuming that the fill water had the same calcium level then as it does now, is it unusual to have a pool that increases 230-240 points in 10 months?

Just looking for alternate sources of calcium to explain the increase and protect against.

Thanks.

22,500 inground, gunite/plaster, poolpilot digital SWG, 45 sq ft DE, 7 foot spa, 1.5 hp pentair pool pump, 2.0 hp pentair spa pump, solar

test results this morning.

Salt 3200
FC 3.0
TC 3.0
Alk 90
Ph 7.4
Cal 430
CYA 40

[waterbear]

Simple answer, you have a gunite pool. If you let your water parameters go out of balance (such as too low a pH for a period of time) it can acutally dissovle the calcium in the plaster of your pool. This is the main reason that calcium is added to plaster pools in the first place. Also you pool is new. Curing plaster can raise the calcium level of the water if I am not mistaken.

[CarlD]

Yup. That's about all there is to it.

[SoCalBoo]

Thanks everyone. Luckily, my Ph has been below 7.2 since startup (fighting high Ph issues with SWG and new pool), so it must just be the new pool issue.

I understand the general consensus is the only way to get rid of calcium from the water is to drain and refill (i.e. dilute it). Anyone heard of anything else.

Moderators - if this should be a new thread because it is a 'new' question, let me know and I'll re-post.

Thanks

[let_her_flicker]

Are you having problems with your pool?

Since you have high CA, is your pool cloudy? You PH is fine according to your other posts. You don't have a heater that could suffer from scaling.

If it was me, I would leave it alone. Why micro-manage your pool. You could possibly end up with more problems.

Just a different point of view.

Good luck with what ever you decide.

[SoCalBoo]

Nah, water is perfect. Crystal clear, no algae in sight, 88-92 for last month or so, FC is stable, CC is non-existant. The BBB method is a thing of beauty.

Get some white deposits (which I assume are calcium in some form) on raised bond beam tile near spillover and in a few other spots, but diluted muriatic and a scrub brush takes care of it. Maybe 10 minutes a month of work.

I can live with the 430 calcium and probably more. My post(s) was/were more directed at the future, because evaporation and refill will slowly cause the calcium to rise. Unless there is a method to lower calcium levels other than draining, I'll need to drain it sometime, probably sooner than I'd like. Since that is the case, I was trying to find out if something went wrong and/or there were ways to protect against high calcium levels to avoid in the future. I take it from the responses that nothing likely went wrong, and there is likely no way to avoid it in the future...just the way it goes, which I can live with.

[SoCalBoo]

Opps, and meant Ph has been above 7.2, above.

[waterbear]

The only problem I can see is the chance of increase scaling in your SWG as the pH rises. There is an alternative to draining and refilling. Calcium is a metal and there are metal sequesterants that are more sepcific for calium than others. Google 'calcium hardness reducer pool' and you should come across several. Just be aware that they do not remove the calcium. Just make it so it cannot react and form scale. Don't know how effective they really are but the chemistry behind them is sound. You will need to keep up with the maintenance doses just like with any other metal problem, however.
I have also seen a product from LoChlor, which Poolsean said was a sister company to AutoPilot Systems, that puts magnesium in the water so the scale that forms on the cell is soft and mushy and will wash off easier. Might want to check with PoolSean on this one.

[let_her_flicker]

You can always check over in the Chlorine Feeder and Salt Water Generator section for scaling issue with SWGs and high CA. I am not familiar with that, but there are others over there that could address that possible issue.

I remember that this site was established to avoid adding other things to your pool. The more chemicals you add, the more problems you could incur. Don't forget that rain water will enter your pool too (hopefully) and that will not have any calcium in it.

Take Care.

Harry

[waterbear]

but, depending on water conditions, some extra chemicals like sequesterants, could be necessary!

[SoCalBoo]

Thanks guys. Just worried about the SWG and the heater (pentair MiniMax NT). Draining 1/2 of the pool and rebalancing frankly sounds cheaper and easier than replacing the heater and cheaper than replacing the salt cell. Admittedly, I have NO idea about how long it would take the elevated level of calcium to render either unusable. Haven't made up my mind yet, so just reviewing my 'options'.

As for rain water, I live in san diego, so not expecting much help there.

[mas985]

SoCalBoo,

I am in a similar situation and just replaced some of my water when my CH got above 400. I started to see some scaling on my SWCG when my PH got above 7.6 so I did a partial refill ~25% and keeping my PH between 7.2-7.4 has so far eliminated the scaling.