Dusty calcium problems after new plaster and start up.

Chappy

Well-known member
May 28, 2008
71
Central Texas
Hey everyone, last month I completed a pool renovation. I re-plastered our pool with Sider-Crete pool plaster. A lot of DIY work, but wow does it look good. Everything is going great after refilling, but I can't get rid of this issue. I'm assuming it's some sort of calcium buildup (silicate?) that's covering the walls and bottom. It's not hard like scaling on tile, more like when you brush it off it clouds up the water. The tricky part is that I can't vacuum it up on the walls since it seems to stick to them and won't budge with the rubber-wheel vacuum head. I'm open to any suggestions to get rid of it. Getting hot here in Austin, TX, but not ready to dip our toes in for another month or so. Thanks!

TA = 80
CA = 50
Can't seem to measure CH, I think the R0011L from my TFP test kit may be bad
Photos attached

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Your PoolMath log has no test results.

Post a complete set of test results including your CSI.
 
How old are your reagents?
What makes you think the R-11L is bad?
Test the CH of your tap water to compare.

If the CH is actually only 50, you are probably slowly dissolving your new plaster
Be sure to select your pool type and chlorinating method.
 
The green R-0011L (which is probably very old like 6-7 years+) for testing calcium hardness if very glompy. When I test both my pool and my home's water, it doesn't turn red at all, it just gets ever so slightly cloudy.

Here are readings I just took. Seems like FC is very high, but I'm only using 3" Trichlor tabs. Obviously I'm doing something wrong and something is out of wack, but I'm not sure what it is. That's why I'm here ;)

It also seems like there are patches of calcium that won't even brush off now. Aye Yai Yai.

FC: 35+
PH: 7.2-7.3
T/A: 80
CH: ?
CYA: 60

Thanks for the help. I haven't been on the forum in years so I may be a little rusty.
 
The green R-0011L (which is probably very old like 6-7 years+)
That reagent does not have a long shelf life. Should be replaced at least every two years.

What is the reported hardness of the fill water from the water utility company?
 
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Have you added calcium to your pool water?

Around 40 ppm is very low CH from the tap.

A plaster pool needs at least 250 ppm of CH to not leach it out of the plaster.
 
The water report shows an average hardness of 240ppm. So I doubt you need more calcium.

You used a product that is not typically used for your plaster. Could that be an issue>
 

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I think I have seen it mentioned once before here on the forum. Not even sure the member used it. It is more like paint than true plaster.
 
I think I have seen it mentioned once before here on the forum. Not even sure the member used it. It is more like paint than true plaster.
Which product are you referring to? The Sider-Crete plaster is not paint. They come in 50lb bags that are mixed up like concrete.
The Calcium Plus product from Leslies is a powder used to raise Calcium levels, which is what I thought I needed to do after following the Sider-Crete opening instructions.
 
Sider crete is rolled on. So it must be somewhat different than normal pool plaster that is mixed, pumped, troweled, and about 1/2 inch thick.
 
Great. Just wanted to point out to others that it was not a conventional plaster application.

The most likely issue is something with the mixture you applied. The water test results do not show anything that would cause what you are seeing.
 
Found this is a city water quality report....View attachment 483927

The "Hardness" in this table is Total Hardness (TH), including Magnesium.

For "Calcium" they don't specify the units properly, whether it is ppm Ca or ppm CaCO3 (which is what is used in the pool world, but ppm Ca is common in water reports). I suspect it's ppm Ca, otherwise you needed an enormous amount of Magnesium in the water to make up the difference between CH and TH.

TH is likely given in units of ppm CaCO3.

To convert ppm Ca into ppm CaCO3, you need to multiply with 2.5, that would give you a CH of about 90 ppm CaCO3. That's still a striking difference between CH and TH, which makes me question the whole water report.

You need to order reagent refills asap and stop guessing.
 
The "Hardness" in this table is Total Hardness (TH), including Magnesium.

For "Calcium" they don't specify the units properly, whether it is ppm Ca or ppm CaCO3 (which is what is used in the pool world, but ppm Ca is common in water reports). I suspect it's ppm Ca, otherwise you needed an enormous amount of Magnesium in the water to make up the difference between CH and TH.

TH is likely given in units of ppm CaCO3.

To convert ppm Ca into ppm CaCO3, you need to multiply with 2.5, that would give you a CH of about 90 ppm CaCO3. That's still a striking difference between CH and TH, which makes me question the whole water report.

You need to order reagent refills asap and stop guessing.
Good idea. I'll do that, and get a calcium test from the local shop in the meantime and return with accurate numbers.
 
If your reagents are that old, you need to order a refill kit for your TF-100.
All the reagents should be replaced at least every 2 years (if the test kit is stored inside the house in a climate controlled environment.
 
Here are all accurate test results from just now. Seems like the main issue now is the build up is getting hard on the surface and won’t brush off. Wonder if there’s anything I can use to remove it (wire brush, chemical)

Thanks!3E7636E4-45C2-4EE1-ACE1-FF5053FD0FF6.jpeg9151C73C-DF43-4502-A993-B198B80EE583.jpeg
 

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