CSI low: Raise TA? Raise CH?

xyz

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Sep 8, 2016
641
Escondido/CA
#1
I realized I had a bad CH measurement in Pool Math. So my current CSI is lower than I'd like. (-0.75).

So I'd like to raise it up to -0.3, or so.

I think the simplest way is to either raise TA or CH.


  1. Am I right? Is there another option?
  2. Now that my water softener is working, I'm only adding Sodium or Potassium Chloride when I fill my pool [Potassium right now]. So I don't know that long term CH growth is as much a concern as it used to be when my fill water was CH130. But I don't have enough time with the new pool surface[AquaBright], and not enough time with this new water [6 pos old]. Since I don't think there is any way to lower CH without a drain and fill, I'm reticent to add CH without advice as to this being optimal.
  3. Or should I raise TA [currently ~80]? My Ph is staying stable, despite this measurement.

Any of our experts have a recommendation either way?
 

pooldv

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#2
I would raise CH to 200-250 and leave TA alone since pH is stable. Raising TA could cause your pH to start rising. Although, I would aim for CSI of -0.6 or -0.5. Is there any tile or grout in the pool?
 
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xyz

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Sep 8, 2016
641
Escondido/CA
#3
The waterline, spa waterline, and spa spillover is tile/grout.

I typically aim for CSI between 0 and -0.3. What would the advantage be of keeping it at -0.5?
 

pooldv

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#4
Just that aggressive water isn't really a problem with AB and it would be a little easier. But, since you have grout then -0.3 is the right number.
 
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xyz

Gold Supporter
Sep 8, 2016
641
Escondido/CA
#6
It is 7.4 right now; it dropped recently, probably because I added CYA to get better protection, now that the sun is climbing higher in the sky, and now that the water is warm.

It has been climbing very slowly so I may also get some aeration going. But if the right answer is to raise TA, I think it might be better to add some bicarb.
 

JoyfulNoise

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May 23, 2015
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#7
Add some bicarbonate and get your TA up another 10ppm or so. Let your pH rise up naturally and keep it between 7.6-7.8. Don't adjust your pH until it rises above 7.8. When you do add acid, don't push it lower than 7.6.


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Patrick_B

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Jun 7, 2011
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Midland TX
#8
I had another post prepared so I'll just say this and differ. If it was mine, I would not worry about it much and let the pH come up a little. If you just enjoy tweaking that's ok, but it isn't needed. The pH rise should easily take care of the CSI number if you are worried about it.

There are times when CSI should be a concern but much of the time it can be ignored.
 

duraleigh

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#9
I would say csi can be ignored the vast majority of the time. I think we pay far too much time micro-managing with csi (that's fine if you like to do that) when what TFP is about is a philosophy of pool care in it's simplest to understand form.

This discussion has been going on for years.....

How important is it to familiarize w/ CSI?
 
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xyz

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Sep 8, 2016
641
Escondido/CA
#10
I would say csi can be ignored the vast majority of the time. I think we pay far too much time micro-managing with csi (that's fine if you like to do that) when what TFP is about is a philosophy of pool care in it's simplest to understand form.

This discussion has been going on for years.....

How important is it to familiarize w/ CSI?

Hmm, interesting advice. I guess I've been watching it closely ever since I set about a quest to get my pool to be, well, not crappy. I had massive calcium scaling [in some places over 1.5" thick], and had major trouble with my SGC scaling. My CH was also very high, and my PH was very high, and my pool maintainer was bouncing the PH around wildly each week.

My pool is so crystal clear, clean, and easy, it is hard for me to even consider easing back on CSI!

However, based on both your and Patrick's advice, I think I CAN ease back on keeping it so tightly regulated.

I think I'll aerate a little, let it drift back up to where it belongs, and call it a day. As time goes on it will slowly creep up anyway, I suspect.

Anyway, thanks for your help, as usual guys!
 

duraleigh

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#11
My CH was also very high, and my PH was very high
Of course, those conditions are the biggest contributor to scaling. Monitoring and controlling your CH with captured rainwater is often the easiest approach. Keeping your pH controlled with muriatic acid is mandatory in ANY pool.

Again, keeping your numbers within the guidelines we suggest will eliminate scaling in most all cases.

How have you started to control pH? Are you actively controlling CH?
 
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xyz

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Sep 8, 2016
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Escondido/CA
#12
Of course, those conditions are the biggest contributor to scaling. Monitoring and controlling your CH with captured rainwater is often the easiest approach. Keeping your pH controlled with muriatic acid is mandatory in ANY pool.

Again, keeping your numbers within the guidelines we suggest will eliminate scaling in most all cases.

How have you started to control pH? Are you actively controlling CH?
This makes sense. With new water [post AquaBright] my CH is very low [150 I think]. I wanted to keep it as low as I could stand, because my fill water was relatively high, and in CA, rain water dilution is a dream that has only happened this spring, and that was not all that much in the grand scheme of things. Said another way, in SoCal, anything you put in the water becomes more and more concentrated over time since

However, I [very] recently fixed [replaced] my Water softener, and the auto fill for the pool runs off softened water.

So... I *think* my desire to keep CH low due to constand addition of CH, is now not really much of a worry--So, I think the final answer I'm getting from you, is, get my CH up to 350, and all will be well [and by the way this will also raise my CSI up into a range I'm more comfortable with]

In other words, if the above makes sense, what you are saying is: keeping the pool math recommend values keeps you in reasonable CSI ranges automatically.

So, add Calcium?
 

Patrick_B

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Jun 7, 2011
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#13
I would not if it were me just to keep it easy. If I wanted to raise CH in that pool, I would simply refill with a hose to bypass the softener for a short time. You aren't going to damage anything by the time it comes up a little.

Edit:

I might also, or alternatively use Cal-Hypo for a Chlorine source temporarily. Its up to you honestly, but its what I would prefer doing as opposed to Micro adjusting TA, or other parameters with chemical additions. Like I mentioned with the natural pH number. Its the CSI that got you concerned right? Simply letting the pH increase naturally changes that value. Without pH consideration CSI values are irrelevant. The pH is a critical part of that puzzle.
 

duraleigh

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#14
So, add Calcium?
Up to you. I wouldn't do it in my pool under those conditions.

Why not just make it a point to observe the grout in your pool and add calcium if there are signs of deterioration. Adding CH to a pool in an area where CH is a problem (I understand about the softener) just goes against my nature and I would be reluctant to do it but I would observe the grout regularly.
 
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xyz

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Sep 8, 2016
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Escondido/CA
#15
Ok, thanks. I think I'm going to do a little of each and see what happens. I like the idea of cal hypo. Instead of kicking up the IC60 during heavy use, I'll just add some, and I'll add a little CH, and I'll let the PH drift up, and I'll aerate.

Sound like a plan?
 

Patrick_B

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#16
Sure, that will work fine. And one thing for sure, you'll get a good feel for what those things do in your pool. Just be on top of it, and make sure you're well stocked on your CH testing reagents pretty soon.