Where'd all my salt and calcium go??

[theseankelly]

Hey TFP -- at pool closing in the fall, I had CH of 450 and salt around 3400. This year at opening, my CH is reading 350 and the salt is down to 2000 -- is this plausible?? I have a 33k gallon pool and we didn't get a ton of rain this winter; I have a hard time believing a third of the water changed over from rainfall/pumping.

Is there a natural process for salt/calcium to dissipate over time? Is it perhaps sitting at the bottom of the pool as precipitate? If so, do I need to wait for my water to get up to temp before truly assessing salt/calcium?

Thanks!
Sean

 

[mknauss]

Nope. Only way to reduce those two items is by exchanging the water with fresh water.

 

[JamesW]

Circulate 24 hours, brush thoroughly and then retest.

 

[theseankelly]

Okay cool, will do.

 

[Bcorig]

In SoCal we had record rain from January to March and the overflow was working constantly for a few weeks. Almost overflowed a few times.
Salt went from 3000 to 2400, CH 360 to 260 and CYA from 60 to < 30 (Taylor 2006) so I'm pretty sure it was the rain.
The acid requirement dropped during those months as well. According to the USGS the pH of Southern California rainwater is 5.5 to 6.0 so I am not surprised by the decreased acid demand due to precipitation.
It likely rained more than you thought.

 

[Newdude]

I have a hard time believing a third of the water changed over from rainfall/pumping.

I pumped out about 2 foot this year instead of the usual 3 foot that we get in the Northeast. This year was 1/3 of an exchange and it's usually half.

My salt was 2200 so yours is about as close as its gonna be.

The CYA lost the same proportion and also the 3 to 5 ppm a month it degrades that isn't seen during the season, but adds up when the pool is closed for 5+ months.

 

[theseankelly]

Thanks all -- My salt came up to 2200 after brushing, but that's only a drop of reagent so effectively no change. I guess I underestimated the amount of rain we received this winter!