Performed a chemical analysis this past weekend suspecting CH problems now that I have scale for the first time in 12 years. FC & CC = 13, pH = 7.5, TA = 100, CH = 330, CYA = 120 ( I know this is high and am working to reduce it). So my question is why do I have a scale issue if my CH is within acceptable levels. In addition to scale at the water line, it is also forming as high as 2-3 inches above the water line (like it is leaching up the grout). If my water is balanced , is use of a scale preventer the next step?
Good CH, still have scale
- Thread starter hampton
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Welcome to TFP.
How did you get those results?
With the numbers you have, if the pH got up a little your csi would be in the scaling range.
How did you get those results?
With the numbers you have, if the pH got up a little your csi would be in the scaling range.
Results were obtained using a TF-100 test kit. I then input the readings into the pool calculator which told me my CSI was ok
Sorry I missed the part about it occuring above the water line.
Do you know what the salt content is?
Can you post a picture of it?
Do you know what the salt content is?
Can you post a picture of it?
Scaling at and above the water line has nothing to do with the water balance. It is an evaporation issue. Evaporation will deposit all elements in water, such as calcium, sodium chloride, magnesium, etc. Pool water splashing up the tile will also eventually deposit enough scale and become visible. The grout can act as a "wick" for water and scale will form much higher than the water line. A scale preventer would not stop this type of scaling.
Acid will remove the calcium, but since this type of scale includes additional things other than just calcium carbonate, it is very difficult to remove the other elements.
If there is water coming from the landscape around the pool and traveling through the pool shell and coming out of the tile, that will also leave a calcium deposit at those places due to evaporation
Acid will remove the calcium, but since this type of scale includes additional things other than just calcium carbonate, it is very difficult to remove the other elements.
If there is water coming from the landscape around the pool and traveling through the pool shell and coming out of the tile, that will also leave a calcium deposit at those places due to evaporation
To Bama Rambler and John T: not a salt pool, and it took acid to get it off although the grout still has a whitish residue. Deposits on the tile were removed with a combination of acid, followed by scrubbing with scotchbrite, followed by a putty knife to remove the stubborn deposits.
To on Balance (the expert!): I don't think water thru the shell is an issue since I only use drip irrigation very sparingly. Is there any additive I can use in the water to minimize the effects of the other elements you refer to?
To on Balance (the expert!): I don't think water thru the shell is an issue since I only use drip irrigation very sparingly. Is there any additive I can use in the water to minimize the effects of the other elements you refer to?
Sorry, but all water contains magnesium, sodium, chloride, and especially calcium. There is nothing that can be added to the water that would remove those elements. They will deposit out when evaporation takes place. There is no way out of that fact. Only distilled water is free of these elements. Adding a chlorine sanitizer continually adds more sodium and chloride, and sometimes other chemicals. As the amount of total dissolved solids (TDS) increases over time, more of a noticeable deposit on tile will occur.
One more question on this topic. Is the purpose of scale inhibitor to slow down the calcium build up where it is not feasible to replace the water with more pure water? If not, what is its purpose? Thanks
Yes, you are correct. The purpose is to inhibit scale formation though as the CH climbs it will take higher levels of calcium sequestrant / scale inhibitor to prevent scaling and at some point you just need to dilute the water to get the CH lower. However, I'm not sure how well such products would work against preventing scale from splash-out/evaporation since the concentration gets very high in that case. They might help only in that they may prevent a "hard" scale from forming if they are designed to interfere with the crystal formation.
I only want to second onBalance and chem geek.
There is no product made or that can be made to stop scale from forming where water wets something and then evaporates.
Scale inhibitors only work on/in areas that are constantly wet or submerged. Only then do they work when everything is kept in balance with pH, TA, mineral saturation, and temperature.
This is just one of those unfortunate absolutes that can't be changed.
There is no product made or that can be made to stop scale from forming where water wets something and then evaporates.
Scale inhibitors only work on/in areas that are constantly wet or submerged. Only then do they work when everything is kept in balance with pH, TA, mineral saturation, and temperature.
This is just one of those unfortunate absolutes that can't be changed.
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