Did i read it was a new plaster pool, you mentioned curing. If your Langleir scale is corrosive it could be pulling the calcium out of the walls of your pool.
Calcium Hardness High
- Thread starter RESISTENCIA13
- Start date
Even if your fill water is 20 ppm, the calcium that is in the pool isn't going anywhere, and every time it fills you are adding ppm of calcium. With no rain and no draining, everyone's CH would eventually get up in the 500 800 1000+ range if they keep levelling the pool with tap water that has some CH in it. Folks on the east coast and up north usually drain for winter anyway, and folks down south get a lot of rain which dilutes the water in the pool.
Those of us in the west, well, none of the above. I'm somewhere between 600 and 1000 depending on your vanishing point but haven't had any scaling yet. Just keep your CSI in check using pool math and adjusting the parameters you can control.
Those of us in the west, well, none of the above. I'm somewhere between 600 and 1000 depending on your vanishing point but haven't had any scaling yet. Just keep your CSI in check using pool math and adjusting the parameters you can control.
Restencia13 has ordered the speed stir. Please note that prior to the TF-100 testing kit, they were using test strips and pool stores and there was a long time period without the recommended test kits.
Maybe there is some error in the CH testing, without the speed stir, as Richard pointed out in his posts. If not, the only thing it could be is the CH levels were low in the beginning and no one advised the homeowner properly and calcium was being pulled from the pool walls. The CH is right around 175, which is exactly what I test and we have the same water company. Hopefully the speed stir will come in and CH tested before the pool is closed.
Hi Guys!
Thanks for the comments/suggestion. So I received my speed stir and retested my water. Since we had rain water and I added water to replace the one evaporated (I started to heat my pool to 90 degrees as it get cool). My CH reading are now 475PM. So not sure if the speed stir made the different or the rain and added it water....my gut feeling tell me a bit of both as I noticed my AK results are now lower than what I used to have. I will take all of your input keep my CSI in check and see what happens next year when I open my pool.
My conclusion is that the speed stir does have an effect on testing (and make it convenience to mix the chemicals without mess and too much efforts). Thanks for all your knowledge and comments to help with my issue.
Thanks for the comments/suggestion. So I received my speed stir and retested my water. Since we had rain water and I added water to replace the one evaporated (I started to heat my pool to 90 degrees as it get cool). My CH reading are now 475PM. So not sure if the speed stir made the different or the rain and added it water....my gut feeling tell me a bit of both as I noticed my AK results are now lower than what I used to have. I will take all of your input keep my CSI in check and see what happens next year when I open my pool.
My conclusion is that the speed stir does have an effect on testing (and make it convenience to mix the chemicals without mess and too much efforts). Thanks for all your knowledge and comments to help with my issue.
Rain and your city water should have little effect on CH given the size of your pool. We can only come to the conclusion of calcium scaling. Well, at least you know how to manage the pool based on CSI. Over time, you should be able to lower CH based on backwashing, rain, winter, evaporation, etc.
At least with the speed stir, it appears that your levels have dropped and may have been off by hand swirling.
I don't follow why you can't conclude definitively if it was the speedstir. Why don't you take the measurement with and without the speedster to see if there is a difference.
Resistencia13 did not have the speed stir and was testing with the TF-100 by hand. There was approximately a 1 year lapse (prior to the TF-100),where the pool store and test strips were being used. CH levels were probably due to scaling and not the city water or adding any type of chemical that increased CH. There was about a 100ppm discrepancy (higher) when the speed stir was not used.
- May 23, 2015
- 24,411
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Read these -
FIVE SOURCES OF ERROR IN WATER TESTING...and what to do about them
TWO WAYS TO IMPROVE DROP-TEST ACCURACY
UNDERSTANDING CALCIUM HARDNESS
RECOGNIZING A COMPROMISED REAGENT
The CH test is one of the hardest (probably second in line to CYA) to perform as it can have a very ill-defined transition of red-purple-blue especially once your CH levels get higher than 500ppm. The drop count starts to go way up (even with the 10mL sample size) and it's easy to lose count of drops or to form undersized droplets. As well, without good lighting, it's hard to see the exact point at which the purple intermediate color transitions to blue. There is also the chance that the indicator dye is getting old and, unfortunately, no way to know for sure if it is bad. Finally, there are metal interferences with this test (Cu and Mg) that can sometimes cause the blue endpoint to not show up at all.
I have 750ppm CH in my pool. I measure CH every few weeks or so and I can easily get +/- 50-75ppm fluctuations. The test is not perfect. I also have a SpeedStir and, while I love it for all the other tests, I find that it doesn't help as much with the CH test because I need to use the 10mL sample size and the stir bar makes it hard to see the solution.
Don't get too worked up about CH. As long as your CSI is within -0.2 to +0.2, you have very little to fear from scaling or plaster etching. Also, being in NJ where you will be constantly draining and refilling your pool as well as battling with rain dilution, the CH fluctuations are the least important parameter to worry about. Keeping your CYA and FC in check will have more effect on overall pool water quality than CH.
FIVE SOURCES OF ERROR IN WATER TESTING...and what to do about them
TWO WAYS TO IMPROVE DROP-TEST ACCURACY
UNDERSTANDING CALCIUM HARDNESS
RECOGNIZING A COMPROMISED REAGENT
The CH test is one of the hardest (probably second in line to CYA) to perform as it can have a very ill-defined transition of red-purple-blue especially once your CH levels get higher than 500ppm. The drop count starts to go way up (even with the 10mL sample size) and it's easy to lose count of drops or to form undersized droplets. As well, without good lighting, it's hard to see the exact point at which the purple intermediate color transitions to blue. There is also the chance that the indicator dye is getting old and, unfortunately, no way to know for sure if it is bad. Finally, there are metal interferences with this test (Cu and Mg) that can sometimes cause the blue endpoint to not show up at all.
I have 750ppm CH in my pool. I measure CH every few weeks or so and I can easily get +/- 50-75ppm fluctuations. The test is not perfect. I also have a SpeedStir and, while I love it for all the other tests, I find that it doesn't help as much with the CH test because I need to use the 10mL sample size and the stir bar makes it hard to see the solution.
Don't get too worked up about CH. As long as your CSI is within -0.2 to +0.2, you have very little to fear from scaling or plaster etching. Also, being in NJ where you will be constantly draining and refilling your pool as well as battling with rain dilution, the CH fluctuations are the least important parameter to worry about. Keeping your CYA and FC in check will have more effect on overall pool water quality than CH.
I got rain water and refilled my pool while waiting for the speed stir. However, after also using it for my FC DPD and AK test, I notice that my drop counts are lower. Hence, I did conclude that the speed stir impacted my test results, just could not give it credit for the entire difference between my original CH reading. When I manually stir the water, my drop count was higher.
- May 23, 2015
- 24,411
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Manual stirring presents the issue of having to swirl the tube with one hand while simultaneously delivering drops with the other. It's tricky to manage even for a seasoned pro. This is where the SpeedStir helps - it decouples mixing from dropping.
The key to a good test is to deliver fully formed droplets at a consistent rate, ~ 1 drop per second. The drop should form slowly at the tip and hang there for a very brief moment, falling off entirely due to its own weight. That ensures the fullest drop volume. Squirting the drops out too quickly or holding the titrant dropper at an angle reduces the droplet volume and can lead to an excess drop count (high concentration error).
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The key to a good test is to deliver fully formed droplets at a consistent rate, ~ 1 drop per second. The drop should form slowly at the tip and hang there for a very brief moment, falling off entirely due to its own weight. That ensures the fullest drop volume. Squirting the drops out too quickly or holding the titrant dropper at an angle reduces the droplet volume and can lead to an excess drop count (high concentration error).
Sent from my iPhone using Tapatalk