Correct way out of balance levels

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Added more calcium and got fresh readings:

CH: 230
CYA: 50
pH: 7.9
FC: 3.4 (I know it's low and just added some)
TA: 150

So it looks like by adding all that calcium, it's spiked the pH upward. Looking at the total balance of the water, it's looking like calcium scaling -could- be a problem. I haven't noticed anything yet but not much time has passed. Do you folks think I should add muriatic acid to drop pH/TA some, or wait it out and see if scaling is an issue? With the temperature of 57F, SI is around 0.35 (with the 1/3 CYA subtracted from 150 TA).

Also, when you guys do a TA test, do you count a "red" change when it first kinda resembles red or when it goes bright red?
 
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Thanks. Using PoolMath and the bright red TA of 160, the CSI is 0.23. Still in the "good" range but will be creeping up outside of bounds as the temperature warms up. I'd still like to get the calcium a bit higher, but the borderline CSI is giving me pause. I'm thinking maybe a little muriatic acid to drop pH to lower end of desired, letting pH creep up over time, and add calcium slowly to not bust through the upper limits of CSI?
 
I dropped some acid and more calcium:

pH: 7.6
TA: 140
CH: 280
CYA: 50
Temp: 58F
CSI: -0.03

I had to use more acid and more calcium (different brand this time) than what the labels say. I'm starting to doubt my water meter saying 15k gal when I refilled, but hard to believe it would be that off. In any case, I might live here for awhile until pH rises and TA drops, then drop in more acid and add calcium (up to 350 max) to keep CSI in a happy place.

Interestingly, I tested the tap water, which is also where I started when I refilled a ways back:

pH: 7.6
TA: 140
CH: 100

I don't know why pH and TA spiked up when I refilled and didn't add anything to do that. Interesting.
 
Which acid are you using ? If it doesn't say 31% on the label it probably half strength

What calcium are you using ?
 

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anothernewpoolguy said:
How does evaporation add calcium?
Click to expand...
When the pool water evaporates the calcium in the pool remains- you then add more water (which also has calcium in it) to replace what evaporated so the overall ch level in the pool will rise each time.
 
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That makes sense. I didn’t think the effect would be that great given how soft my tap water already is. This will be my first summer so I can monitor how much topping off is needed and I’ll test through the season. So what does everyone do after the summer season and CH spikes? Partial drain/refill?
 
anothernewpoolguy said:
That makes sense. I didn’t think the effect would be that great given how soft my tap water already is. This will be my first summer so I can monitor how much topping off is needed and I’ll test through the season. So what does everyone do after the summer season and CH spikes? Partial drain/refill?
Click to expand...
CH: 100 -- that is not 'soft' water.

In areas of high CH fill water and high evaporation, many of us use softened water for pool fill water. Or you must drain and refill when the CH rises too high.

Your evaporation may not be extreme, but I suspect it is not insignificant.
 
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Thanks, we'll see how the summer season goes. I want to get proactive in getting my TA down. I've read about the acid and aeration method. My question is what would be a more energy efficient method to aerate: air or water jets? Aquarium type aerators are cheap and seem to provide a lot of bubbles at low energy usage. Aerating with water jets/falls/etc uses more energy, increases evaporation, and lowers temps. All of those are undesirable to me.
 
Ok, I don't know what's going on with my CH levels. I've always had to add a bit more than the packaging/calcs say. A few days ago I measured it at 250, then added more over the next few days and it went up to 270, then unsurprisingly at 300 yesterday. Today it's at 240 when no new calcium was added since yesterday. I measured it twice in different locations of pool with same result. Pump has been running. I don't think it's user/testing error. I should mention we had some pretty heavy rain last night.

Where is the calcium going? Is it possible it's reattaching somewhere? Before I did the complete refill, the water CSI was WAY on the corrosive/aggressive side (like more negative than -3.24 since I couldn't measure pH lower) and it must have been that way for years. Could it be rebuilding on the plaster walls?
 
My pool chemistry has leveled off with a good CSI. Thanks everyone for the help through the process. My TA is still on the high side so it's pushing my pH up pretty quick, which I'm keeping in check with acid. My calcium is still on the low side (230 ppm). It's still gone down some for whatever reason, but that rate seems to have steadied some.

Since calcium in the water by itself seems to have little practical value outside of helping to push up CSI, why not keep calcium levels low and keep CSI pushed up with higher TA levels? I know the high TA level drives up the pH ceiling so the acid demand will be higher, but what if CSI was maintained with acid/baking soda instead of higher calcium levels?
 
I suspect CH testing variance is likely just user error. Do you have a speed stir device?
TA is best fought with fairly aggressive acid additions. Once pH hits 8.0, lower to 7.0-7.2 and you'll find that the pH bounces up fairly quickly with the necessary TA reductions. I have high TA well water, so I fight this each summer. 1 gallon of acid for each 1" or so of water I add.

CH in water protects pool surfaces (plaster most of all) but also is a part of managing CSI which is important if you have a salt water chlorine generator. If you don't have a SWCG - I wouldn't be too concerned as long as you manage pH and most importantly, FC/CYA.
 
I use a Taylor 2006 kit and a magnetic stirrer. I'm not so sure it's user (me) error. The addition of calcium and its measurement seemed to be consistent, just low compared with calculated values. The "lower than label said" could be a function of smaller than assumed pool gallonage. The mystery part is why it's dropping (much slower now). I'm not adding any new water. I don't have a SWCG. One possibility that I have no idea of possible, is if the calcium is being deposited on the walls/plaster. The previous owner had water in it that was SUPER negative CSI for years. Super high CYA, low TA, low CH, stupid low pH. I'm wondering if the walls got etched and they want revenge.

I haven't been too aggressive with bring TA down, partly because of mknauss's suggestion and partly because I can see the effect lower TA would have on my CSI. Since my CH is already on the low side (230 ppm), knocking down TA too aggressively will eventually require me to add CH to keep pH and CSI in a happy place. My left field thought about keeping CSI up by regulating pH/TA with acid/baking soda was to avoid what will be the eventual need to add CH. I'm going to guess the primary reason not to do this is the amount of additional continual acid needing to be added to keep fighting with high TA makes it not friendly to the wallet.

This was an interesting read:

blog.orendatech.com

Ideal Calcium Hardness and Total Alkalinity Levels in Pools

Balance water easier with a favorable ratio of ideal calcium hardness to total alkalinity (CH: TA). Experience shows us a minimum of 3:1 improves pool chemistry
blog.orendatech.com blog.orendatech.com
 
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