curious about Ca+

[pedsrn]

My pool is vinyl, so I hardly ever check Ca+. I did check it today and noticed it is 60. It was well over 200 last August. I'm curious as to how that happened???

[jen in tx2]

So what should my TC level be at various CYA levels?

[pedsrn]

I cut and pasted this from a post by watermom. I think this is what you're asking:

Best Guess CYA chart


Ben's 'best guess' FC/Stabilizer table for algae free operation of OUTDOOR pools -- as of July 2003 --

Use the info in this chart to help you figure out what levels of chlorine you need to maintain in your pool based on the amount of CYA (cyanuric acid, also called stabilizer) that you have in your pool. (FC = free chlorine)

Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
=> 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
=> 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
=> 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
=> 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
=> 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm

[mwsmith2]

pedsrn,

Ca gets lowered 3 ways:

Splash out
Pump out
Drag out

So, if your water level has changed in any way, that's where your Ca went.

Michael

[PoolDoc]

My pool is vinyl, so I hardly ever check Ca+. I did check it today and noticed it is 60. It was well over 200 last August. I'm curious as to how that happened???

Possibilities:

• Leakage / splashout, followed by water replacement. (Not very likely, since it would require that you lost 75% of your water in a single episode, or even more, if you lost, say, 50% per episode.
• Scaling / precipitation. (Is your pool slimed, with what feels like sand on the liner / ladder / light rings under the slime?)
• Testing error. (Have you changed test methods, or replaced old test strips with new ones? Test strips are inaccurate, but get much worse over the summer as moisture from the air or your fingers causes them to deteriorate.

There may be some additional possibilities, but those are all I can think of at the moment.

Ben
"PoolDoc"

[HooStat]

One thing to do is test your water supply. There are generally only 2 sources of water for most pools (aside from trucks used to fill): city water (or well water) and rainwater. Rainwater is going to be about 0 for calcium and your tap water will vary by region (ours is 110). But if you are filling with tap water when the levels get a little low, that represents the lowest amount that you should see for the pool calcium level.

[pedsrn]

Hmmmm, I don't know. We haven't drained and refilled and the test I'm using is the ps233. Perhaps my reagent is bad. I'll retest after I get the 234. No, Ben, I swam this past week and didn't notice any slime or scaling <shrug>.

anyhoo, thanks for the replies!!