Still getting scaling on spillway

Romoth

Well-known member
Sep 18, 2020
49
Houston, TX
Some of you have suggested some automation help to stop running the spillway so much. I went ahead and did that, and noticed that I'm still getting scaling at the waterline of my wall. I think I had some bad reagents in my test kit because I got new ones and my CH shot up about 125 points. I ran multiple tests with slightly different answers and finally just went to a Leslie's to see what their automated process spat out. I didn't buy anything, but definitely wanted to make sure I wasn't losing my mind!

NameTFT Test KitLeslie's
Free Chlorine66.3
Total Chlorine07 (not super concerned, just interesting)
PH7.87.8
CH475473
CYA4036
CSI.18

I clearly over-added calcium. Is this level worth doing a partial drain? PB said I could do that by hooking up a water hose to the hose bib on top of the filter to ad rain. Close the skimmers and let it slowly drain from the bottom while I fill from the other end (theoretically). For reference, my fill water CH here in Houston proper is apparently only 100CH. I welcome any thoughts because I'm exhausted cleaning scale and I'm starting to have some serious second thoughts about having bought this thing! Thank you in advance.
 

ajw22

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Jul 21, 2013
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Your CSI is too high.

What is your TA?

Keep your CSI between 0 and -0.3 to prevent scaling. The lower CSI the better.
 

mknauss

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By wall is that below the spillway to the pool? You will get evaporate scale there no matter what. Lowering the calcium level some will reduce it, but not eliminate it. You get rain in Houston so just lower your pool level an inch or two prior to each rain and let the rain fill it up.
 
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Romoth

Well-known member
Sep 18, 2020
49
Houston, TX
My TA is 80 from my test and 72 from Leslies. Forgot to add that! @mknauss the scale is where the spillway meets the pool. If it's a common problem, how do you clean it? I'm pouring a little bit of muriatic acid on it and letting it sit for about 30 seconds and it kind of gets rid of it (at least above the waterline), but how do you keep it down below the waterline? That's great advice on lowering it. I'll do that and it should let me get to the stuff below the current waterline to clean it up. Should I also be brushing multiple times per week there, or does that not help it? I'm currently doing a really good brush once a week.

And I'm having a Darn hard time keeping my CSI anywhere consistent. Houston's temperatures have mood swings and it jumps around a lot. I'm assuming, I should be angling for a lower PH (7.6ish) to manage this?
 

mknauss

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If the scale is below the waterline, then the CSI has been much higher in the recent past.

Maintain your levels as shown in Recommended Levels.

Do realize we only believe your test results. I did not even look at the pool stores.
 

Romoth

Well-known member
Sep 18, 2020
49
Houston, TX
Ok, so I think the bit below the waterline came from when I heated the whole pool up. I had the CH at 350 and if it was 475, my CSI would definitely have caused scaling there. I normally rely on my testing, but with the varied results I was getting, the comparability made me feel a little better that my results were accurate.

As far as the scale on the waterline, what I'm hearing is that I need to maintain a slightly negative CSI (even though it says +-.3, I need to be on the negative side of that). Is that enough, or does brushing actually help that at all. This scale issue has me freaking out that I've ruined my pool. Thanks gain.
 

mknauss

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You have not ruined your pool. Us in the SW desert have some form of waterline scale essentially always. Our evaporation rates and high CH fill water dooms us to it. It is cosmetic.

You can keep your CSI a bit lower. Again, it might reduce the scale, but not eliminate it. Pool structures are built for looks. Pool builders are clueless on pool water chemistry. Splash zones and areas that get wet and dry often will get scale.
 

ajw22

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Jul 21, 2013
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Northern NJ
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Scale can always be removed. So you are not going to ruin your pool that way. It just may cost you some money if your elbow grease is not sufficient.

 

Romoth

Well-known member
Sep 18, 2020
49
Houston, TX
Ok, well I've used some straight MA and a screwdriver (gently) to chip off what was there in the grout and I'll just keep an eye on it. For whatever reason, I'm pretty neurotic about this (as people who've helped me before can probably see!), so thank you for all the help.
 

mknauss

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Laughlin, NV
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Use a pumice stone versus a screwdriver. Also be careful on the use of muriatic acid as it will attack the grout as much as it does the scale.
 

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Romoth

Well-known member
Sep 18, 2020
49
Houston, TX
Ok, I'll grab a pumice stone. Thanks. Should I be using something like a 3:1 on the muriatic acid? What else do you use to soften up the scale?
 

mknauss

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A lessened acid concentration is easier to use so a good idea.

Our pool only has water line scale. It stays off the tile but does build up on the grout (as the water imbibes above the water line and evaporates). I have not done much about it, but sounds like I will be using a pumice stone this spring as the DW is making noises about it.
 

Romoth

Well-known member
Sep 18, 2020
49
Houston, TX
One last question, and thank you again for all the help. How does this impact my usage of the spa? I notice that when I input a temperature of 99 or 100 into the pool math app, I'm at about .3 CSI. Will the spa scale that fast, or is the short time frame it's used enough to mitigate that risk?
 

mknauss

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May 3, 2014
35,937
Laughlin, NV
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Scale is not an instantaneous occurrence in pools. So I would not concern yourself with it based on spa use.
 
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iamtexmax

Bronze Supporter
May 25, 2018
94
Austin
Some of you have suggested some automation help to stop running the spillway so much. I went ahead and did that, and noticed that I'm still getting scaling at the waterline of my wall. I think I had some bad reagents in my test kit because I got new ones and my CH shot up about 125 points. I ran multiple tests with slightly different answers and finally just went to a Leslie's to see what their automated process spat out. I didn't buy anything, but definitely wanted to make sure I wasn't losing my mind!

NameTFT Test KitLeslie's
Free Chlorine66.3
Total Chlorine07 (not super concerned, just interesting)
PH7.87.8
CH475473
CYA4036
CSI.18

I clearly over-added calcium. Is this level worth doing a partial drain? PB said I could do that by hooking up a water hose to the hose bib on top of the filter to ad rain. Close the skimmers and let it slowly drain from the bottom while I fill from the other end (theoretically). For reference, my fill water CH here in Houston proper is apparently only 100CH. I welcome any thoughts because I'm exhausted cleaning scale and I'm starting to have some serious second thoughts about having bought this thing! Thank you in advance.

I am having the same issue here in Austin...have not been able to remove the scaling:

Free Chlorine - 5
pH: 7.5
cYA - 35
CH - 525
TA - 70

Have tried cleaning with diluted Muriatic Acid to no effect....just resigned to my fate... wish I had not put glass tiles...
 

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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
35,937
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
wish I had not put glass tiles...
They can be problematic. Is that scale at or above the waterline? Looks more like efflorescence.
 

iamtexmax

Bronze Supporter
May 25, 2018
94
Austin
It is way above the water line....looks ugly and have been unable to remove with diluted MA - it maybe efflorescence....I have scrubbed till my hands are raw....used pumice stone....nothing works to get rid off it....talked to a few pool companies if they can help....but no luck...😪
 

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