CH getting really high, TA getting low

[voidpointer]

Hey folks,

My CH is getting extremely high and I can't help but assume I'm messing up the test, although I don't feel like I've been doing the test differently since I started doing it in March when my pool finished. Looking at my own poolmath logs, the timeline looks like this:

Now: 675
1 month ago: 525
2 months ago: 450
3 months ago: 400
4 months ago: 400
5 months ago: 375
6 months ago: 300
7 months ago: 275

The rate of increase month-to-month up until 3 months ago was roughly 25-75ppm. The jump in September was 75, and this month it is 150?? I'm really confused. I adjusted my test for the fading endpoint as instructed here. I found that without this, as I dropped R12 in, it was really difficult to see when the final endpoint was met. I am barely able to notice the color changing and my brain sometimes can't tell if I'm staring at purple or blue. I personally feel like this test is harder and more subjective than CYA.

Does the CH test become harder / less accurate as CH gets higher? Assuming I'm not doing the test wrong, I can't explain the numbers. I know here in North Dallas we have hard water, but I expected to see a more or less linear increase. It's odd to me in the hottest months this year, where we had pretty much no rain, that I'm not seeing a significant increase in CH.

I think I want to iron out the how & why before I move the discussion to draining my pool. Never had to do it before, and I feel like I'm going to have to do that before the year is out.

Regarding my TA: It's finally hit 50. It's been stuck at 60 for several months. Is it time to add baking soda? Normally I'd just do it, and not ask, but I was warned to "not be a slave to the app" and it's caused me to doubt myself a lot more. I don't know squat so I rely on Pool Math to know when I need to do a thing.

 

[Bperry]

Hey folks,

My CH is getting extremely high and I can't help but assume I'm messing up the test, although I don't feel like I've been doing the test differently since I started doing it in March when my pool finished. Looking at my own poolmath logs, the timeline looks like this:

Now: 675
1 month ago: 525
2 months ago: 450
3 months ago: 400
4 months ago: 400
5 months ago: 375
6 months ago: 300
7 months ago: 275

The rate of increase month-to-month up until 3 months ago was roughly 25-75ppm. The jump in September was 75, and this month it is 150?? I'm really confused. I adjusted my test for the fading endpoint as instructed here. I found that without this, as I dropped R12 in, it was really difficult to see when the final endpoint was met. I am barely able to notice the color changing and my brain sometimes can't tell if I'm staring at purple or blue. I personally feel like this test is harder and more subjective than CYA.

Does the CH test become harder / less accurate as CH gets higher? Assuming I'm not doing the test wrong, I can't explain the numbers. I know here in North Dallas we have hard water, but I expected to see a more or less linear increase. It's odd to me in the hottest months this year, where we had pretty much no rain, that I'm not seeing a significant increase in CH.

I think I want to iron out the how & why before I move the discussion to draining my pool. Never had to do it before, and I feel like I'm going to have to do that before the year is out.

Regarding my TA: It's finally hit 50. It's been stuck at 60 for several months. Is it time to add baking soda? Normally I'd just do it, and not ask, but I was warned to "not be a slave to the app" and it's caused me to doubt myself a lot more. I don't know squat so I rely on Pool Math to know when I need to do a thing.

You’re keeping your pH a little lower than necessary and so the calcium may be coming from your plaster. See if you can keep the CSI a little closer to zero. Let pH stay closer to 7.8 and it’ll reduce the need to mess with the TA. It’s fine at 50 but don’t let it go lower.

 

[voidpointer]

Ok, that's an interesting observation. I didn't suspect that at all since the target range for pH in PoolMath for me is 7.2-8.0. I was told to not let it go above 8. And I didn't want to have to add MA every day (I already have to add it every other day). After I add I'm typically at 7.5. My test kit doesn't measure 7.6. pH is already a huge pain in the rear to maintain right now.

Maybe this explains why my plaster looks more spotty / stainy now. I wasn't sure if it was the pH or just the aging process. Or maybe it was always there and I'm just seeing things.

So you're saying I need to keep it between 7.8 and 8.0? That means I'll be adding MA daily, I'm pretty sure. My test kit does not measure 8.0. I can see 7.8 or 8.2. So I am not sure how I'm going to go about this.

 

[voidpointer]

See if you can keep the CSI a little closer to zero

I kind of get what CSI is, but I don't really know for sure. Above 0 means calcium build up, below means it'll get pulled from plaster. But I don't know what actions I need to take to manipulate the CSI to a specific and desired range.

 

[ajw22]

Are you doing a SLAM?

Why is your FC so high?

 

[ajw22]

I kind of get what CSI is, but I don't really know for sure.

Have you read -

Calcium Saturation Index (CSI)

How is CSI calculated? Very simple – use our PoolMath tool. To ensure long plaster life and save money, click here to learn more.

www.troublefreepool.com

 

[voidpointer]

Are you doing a SLAM?

Why is your FC so high?

I had a busy last 7-10 days and didn't test my FC. Weather has been getting cooler and I haven't been keeping my SWG percentage low enough. It creeped up to 15ppm and I turned it off. No one uses the pool right now anyway. I'm waiting on it to naturally lower to more ideal levels then I'll turn it back on and keep a closer eye on where my percentage needs to be.

 

[ajw22]

But I don't know what actions I need to take to manipulate the CSI to a specific and desired range.

Best level to control CSI is pH. Higher pH will cause higher CSI.

You want to keep you CSI between -0.6 and +0.6, preferably between -0.3 and 0.

You have been lowering your pH between 7.2 and 7.5 which lowers you CSI. Run your pH between 7.8 and 8 to keep your CSI up.

Also colder water will lower your CSI. So higher pH is preferable in the cooler months.

Leave your TA at 50 and stop adding so much acid.

 

[ajw22]

With high FC the pH test is invalid and other tests can get funky.

Just leave your water alone and let your FC drop and pH drift up.

Retest once your FC is below 8.

 

[voidpointer]

Have you read -

Calcium Saturation Index (CSI)

How is CSI calculated? Very simple – use our PoolMath tool. To ensure long plaster life and save money, click here to learn more.

www.troublefreepool.com

I just read it, thank you for that. The most helpful part was where it suggested playing with the CSI in pool math. I completely forgot it shows the CSI value at the bottom before submitting the test results. Looks like 7.8-8.0 is indeed the best way to keep CSI between 0 through -0.3. I wish my test kit for pH had more granularity, but I assume anything between 7.8 and 8.2 will be ok.

You have been lowering your pH between 7.2 and 7.5 which lowers you CSI

This wasn't intentional. I think this is a result of me being really bad at "eyeballing" 32oz when I pour it directly into the pool. I'm going to use pool math to recalculate how many ounces to add to get to a target of 7.8. It'll surely be less, so I'll have to try to get better at the guesswork.

With high FC the pH test is invalid and other tests can get funky

I didn't know this, but it helps answer a lot of questions.

I think overall, the season shifting to colder weather has been a difficult adjustment for me. All through summer I felt like I was doing great and didn't have any problems. But I didn't adjust my behavior to compensate for the colder weather. This is my first "hot -> cold" transition since the pool finished, so I'll need to learn again!

I really appreciate the help as usual.

 

[Bperry]

I just read it, thank you for that. The most helpful part was where it suggested playing with the CSI in pool math. I completely forgot it shows the CSI value at the bottom before submitting the test results. Looks like 7.8-8.0 is indeed the best way to keep CSI between 0 through -0.3. I wish my test kit for pH had more granularity, but I assume anything between 7.8 and 8.2 will be ok.

This wasn't intentional. I think this is a result of me being really bad at "eyeballing" 32oz when I pour it directly into the pool. I'm going to use pool math to recalculate how many ounces to add to get to a target of 7.8. It'll surely be less, so I'll have to try to get better at the guesswork.

I didn't know this, but it helps answer a lot of questions.

I think overall, the season shifting to colder weather has been a difficult adjustment for me. All through summer I felt like I was doing great and didn't have any problems. But I didn't adjust my behavior to compensate for the colder weather. This is my first "hot -> cold" transition since the pool finished, so I'll need to learn again!

I really appreciate the help as usual.

Also, keeping your pH a bit higher will help you not need to add acid so much. As the pH gets closer to its natural “happy place”, the rise slows down a lot. It doesn’t increase linearly so the farther you push it down, the faster it’ll start to rise.

 

[voidpointer]

Also, keeping your pH a bit higher will help you not need to add acid so much. As the pH gets closer to its natural “happy place”, the rise slows down a lot. It doesn’t increase linearly so the farther you push it down, the faster it’ll start to rise.

Well, I've also been dealing with new plaster since March as well, so I'm not really sure where that happy place is yet. So far, it's been well above 8.2 which I was told to not let it get to. So if the happy place is higher than that, I don't think I'll see pH level out like you suggest.

 

[PoolStored]

Well, I've also been dealing with new plaster since March as well, so I'm not really sure where that happy place is yet. So far, it's been well above 8.2 which I was told to not let it get to. So if the happy place is higher than that, I don't think I'll see pH level out like you suggest.

This is a critical piece of information (new plaster)...add it to your signature.

New plaster will cause pH rise for 6-24 months. Monitor your pH more frequently.

When your pH rise slows due to plaster curing, then you will find your pH will find a happy place (as @Bperry indicates) with TA between 50-80. Until then, monitor pH.

 

[Bperry]

Well, I've also been dealing with new plaster since March as well, so I'm not really sure where that happy place is yet. So far, it's been well above 8.2 which I was told to not let it get to. So if the happy place is higher than that, I don't think I'll see pH level out like you suggest.

Yes. New plaster pH rises faster than normal but if you don’t try and drive it down to 7.2 you’ll find it much easier. Let it get up to 8.2 and then knock it back down to 7.8 or so. See how that does.

I just had my plaster redone 30 days ago and the pH rise is very slow. Seems abnormal almost, but I’ve got a lot of calcium in there and I’ve been floating some trichlor pucks as well so that may be part of it.

 

[ajw22]

. So far, it's been well above 8.2 which I was told to not let it get to.

Nothing bad happens if pH gets to 8.2 or above. Just don’t leave it there. Reduce it back into the 7’s.

So if the happy place is higher than that, I don't think I'll see pH level out like you suggest.

Some pools never get to that happy place.

You have to learn what works for your pool environment. Don’t mimic other people.

 

[mgtfp]

Not sure if I like to see CH still rising a couple of months after the plaster was applied. Maybe @onBalance has some insight?

 

[onBalance]

Aggressive water that has a negative CSI of around -0.8 would dissolve and remove calcium from the plaster finish and raise the calcium level of the water by about 50 ppm over six months time.

As we all know, evaporation of the pool water and adding more tap water increases the calcium level. And adding any product that contains calcium also increases the calcium level such as calcium hypochlorite.

The speed of which your calcium level is rising is very fast. It is possible that the plaster finish is of low quality.

 

[voidpointer]

Is it concerning that I see what I believe to be pebbles from the plaster stuck in the cleaner filter basket mesh? I always thought it was dark colored sand but it might be the plaster

 

[voidpointer]

Here's a pic. Maybe it is just sand. I'm not concerned with the red stuff. That's very clearly sand. But there's some white and black in there too.

 

[reggiehammond]

Are you on city water or well water? Have you tested for your fill water CH?
I ask because this summer was hot, and extremely dry. Lots of fill water used to maintain level...