aeration vs. "pH Up"

[ajw22]

The member has a SWG. Shouldn't he get it to 70 to 80?

Not necessary in the Northeast this time of year as the sun angle is decreasing.

70 to 80 is necessary in the Southwest. 60 is passable in the Northeast, especially in August and beyond.

The maximum sun angle is late June and sun intensity declines from there into the Winter.

 

[cledee]

I think it comes down to hours uncovered.

FC losses will be higher when uncovered, at the lower CYA. But with a cover installed, losses are minimized, and lower CYA lets me run lower FC... and probably net a little less CC.

Did I get that right?

I see. Yeah then not necessary to increase CYA since you wouldn't gain much in this situation.

 

[cledee]

There is no need with a pH of 7.8 to drop the pH to 7.2 - unless you like spending money on acid or trying to keep CSI slightly negative to prevent SWG scaling (usually because of a high CH).
There is no need to force TA down or pH down unless you have scaling. But then, you need to determine the need and plan on what to do. Haphazardly lowering pH serves no purpose.
Many times, letting the pH ride at 7.8 to 8.0 will result in a stable pH without the need to force anything.

After doing more reading, it appears that you could even operate a pool at the 7.8 to 8.2 PH range, as long as you have CYA, you don't have a high Calcium or high Alkalinity and you don't have metals in your pool such as iron/copper since this will cause things to precipitate over your pool. As long as you understand all your level through testing you can go from 7.0 to 8.2 PH with no issues. I'm constantly learning new things every day.

 

[reggiehammond]

After doing more reading, it appears that you could even operate a pool at the 7.8 to 8.2 PH range, as long as you have CYA, you don't have a high Calcium or high Alkalinity and you don't have metals in your pool such as iron/copper since this will cause things to precipitate over your pool. As long as you understand all your level through testing you can go from 7.0 to 8.2 PH with no issues. I'm constantly learning new things every day.

What does CYA have to do with pH? I'm not sure I follow what you feel like you now understand...

 

[cledee]

What does CYA have to do with pH? I'm not sure I follow what you feel like you now understand...

CYA determines what percentage of chlorine is active in the water, so you can let PH climb as high as 8.2 with no issues, if you don't have metals or high calcium level in your water.

@proavia said, there's no reason to just lower PH at 7.8 or even 8.0 since they may stay there for a very long time.

 

[proavia]

CYA determines what percentage of chlorine is active in the water, so you can let PH climb as high as 8.2 with no issues, if you don't have metals or high calcium level in your water.

@proavia said, there's no reason to just lower PH at 7.8 or even 8.0 since they may stay there for a very long time.

How much CYA is in the water has nothing to do with pH.
It is only when initially adding stabilizer that the pH will drop a little.

My statement about not lowering pH was that you don't lower it just for the sake of lowering it.
If pH is stable in the 7.8 to 8.0 range and all your other parameters are good - leave pH alone.

 

[cledee]

How much CYA is in the water has nothing to do with pH.
It is only when initially adding stabilizer that the pH will drop a little.

My statement about not lowering pH was that you don't lower it just for the sake of lowering it.
If pH is stable in the 7.8 to 8.0 range and all your other parameters are good - leave pH alone.

@proavia
I wasn't talking about CYA affecting your PH levels. I was talking about CYA controlling your chlorine's strength. So you can allow your pool's PH to rise even as high as 8.2 if that's your pools stable level and have no issue with chlorine keeping your pool sanitized. Then you don't have to keep putting acid in the pool unnecessarily. Obviously for new users, you should follow the guidelines 7.2-7.8 until you are more comfortable with your pool.
@reggiehammond
It was my new understanding of CYA's control over chlorine strength and the role PH plays. I know that without CYA, lower PH will mean more chlorine active in your water. Higher PH means about half active. PH above 8.0 means about 10% or less. This changes with just 30ppm of CYA, nearly 97-98% of chlorine is bound to the CYA, so PH is less important to chlorine strength. Which is why if your PH is 8 and it doesn't go higher than 8, there's no need to just add acid to get it to 7.2.

Maybe what I'm saying should go in another thread. I'm just trying to explain what I've learned from reading ect. Sorry to hijack the post.

 

[ajw22]

@proavia
I wasn't talking about CYA affecting your PH levels. I was talking about CYA controlling your chlorine's strength. So you can allow your pool's PH to rise even as high as 8.2 if that's your pools stable level and have no issue with chlorine keeping your pool sanitized.

There is no effect on your chlorine if your pH goes over 8.2

You are confusing things.

@reggiehammond
It was my new understanding of CYA's control over chlorine strength and the role PH plays. I know that without CYA, lower PH will mean more chlorine active in your water. Higher PH means about half active. PH above 8.0 means about 10% or less. This changes with just 30ppm of CYA, nearly 97-98% of chlorine is bound to the CYA, so PH is less important to chlorine strength. Which is why if your PH is 8 and it doesn't go higher than 8, there's no need to just add acid to get it to 7.2.

Once you have CYA in the water pH has little effect on chlorine effectiveness.

Maybe what I'm saying should go in another thread. I'm just trying to explain what I've learned from reading ect. Sorry to hijack the post.

Keep your confusion on this thread.

 

[cledee]

There is no effect on your chlorine if your pH goes over 8.2

You are confusing things.


Once you have CYA in the water pH has little effect on chlorine effectiveness.



Keep your confusion on this thread.

I mean there's a small effect, but not noticeable. talking 1 percent at most.
typically with 30ppm cya 97% of your chlorine is bound with a PH of 7.5, but at PH of 8.0 means that 98% of your chlorine is bound.

I got this information from here. I'm not promoting anything. Just trying to show you where I got my information.

Chlorine, pH and Cyanuric Acid Relationships

pH controls chlorine strength (% HOCl), but NOT when Cyanuric Acid (CYA) is in the pool. CYA takes over control of chlorine strength. Did you know that? Chlorine and cyanuric acid.

blog.orendatech.com

 

[ajw22]

I mean there's a small effect, but not noticeable. talking 1 percent at most.
typically with 30ppm cya 97% of your chlorine is bound with a PH of 7.5, but at PH of 8.0 means that 98% of your chlorine is bound.

I got this information from here. I'm not promoting anything. Just trying to show you where I got my information.

Chlorine, pH and Cyanuric Acid Relationships

pH controls chlorine strength (% HOCl), but NOT when Cyanuric Acid (CYA) is in the pool. CYA takes over control of chlorine strength. Did you know that? Chlorine and cyanuric acid.

blog.orendatech.com

1% is less then your accuracy for any of your water tests.

We are playing a game of close enough within broad ranges is all you need to care about.

 

[cledee]

thank you @ajw22 @proavia appreciate the back and forth.

 

[P00LNerd]

Okay, some updates:

Despite continual aeration via one return turned skyward, pH seems to hold pretty steady around 7.4 - 7.6. You can see all of my chemical adds (or lack thereof) in PoolMath.

I used up the 2 lb. of Dichlor I had in the cupboard, mostly just to get rid of it and toss the bottle. It helped with FC for two days, and added a miniscule amount of CYA. PoolMath says my CYA is low, the importance of which varies with the weather, as my use of solar cover is very weather-dependent. It's been off noon - dusk most days this week, only installed to minimize overnight temp loss.

I'm wondering the best way to use PoolMath with logging SWG adds, whether to log at the beginning of a programmed cycle or the end of it. I really think the software could be set up much better here, to just input current setting and model, and let the real time clock in the software determine duration... rather than asking the user to either predict or remember the duration, when calculating total Chlorine addition.

 

[proavia]

PoolMath is just a calculator.
YOU need to give it the info so it can calculate for you.

Just enter your testing results - and try to test at the same time each day.
After a week or so, you'll get a better feeling for how much FC you pool uses each day as the sun's intensity, cloud cover, etc is different each day. You don't log SWG adds - you log FC test results and adjust the SWG accordingly.

There is zero need to micromanage the SWG perrcentage or run time. If the FC gets a little high, that's just fine. It is safe to swim when FC is between minimum and SLAM level for your CYA - and you can see the entire bottom of the pool (swimmer safety).
Just don't let the FC fall below the lower end of the target range - always dose for the high end of the range (or a bit higher if there is a high bather load). And never, ever let FC fall below minimum at any time.

It's just pool water and close is close enough. We aren't making rocket fuel.
Many of us only adjust our SWG every couple of weeks or less. SWG percentage goes up in spring and summer, down in fall. As the temps cool the pool water to 60 or less, monitor to see when the temps are too cold for the SWG to make chlorine - and use liquid chlorine during that time. As temps warm the pool water, turn the SWG back on to start the cycle all over again.

Your CYA is 60 - you need to get the FC toward 9. The FC of 3 your reported is too low. You also reported previous results where FC fell below the minimum of 3. Dose with liquid chlorinne to get to FC 9 and maintain that with the SWG.

What is the pH, TA and CH of your fill water?
You may have already posted that, but I don't want to go thru 50+ posts to find it.

 

[P00LNerd]

Thanks! I haven't added fill water in a few months, we've been getting plenty of rain. But when I do, the TA and CH are:

CH = 150-160 ppm
TA = 170 - 180 ppm

I'll have to check pH, haven't ever bothered, but also haven't added water in too long for it to matter.

 

[P00LNerd]

Oh, forgot to address test time. I test every evening before dusk, usually 7pm - 8pm. But since I'd been getting low readings the last few evenings, which really didn't make sense given SWG setting and historic losses, I decided to do a morning test or two in-between, figuring FC should be maximized at dawn and minimum at dusk, with pump always running.

I ran SWG at 30% - 35% my first few days, and FC went absolutely thru the roof. Now I'm running at 15% - 20%, which by Effects of Adding should be higher than I need. but still coming in low. Not sure why.

My typical FC losses are 0.5 - 1.0 ppm with cover on, or 2.5 - 3.0 ppm/day with cover off.

 

[P00LNerd]

PoolMath is just a calculator.
There is zero need to micromanage the SWG perrcentage or run time... Many of us only adjust our SWG every couple of weeks or less.

I was thinking about this as I covered the pool last night. It had been hot for 3 days, so I had the cover off a lot, but it's going to be cool and rainy the next 3 days, so the cover will likely stay on.

I can lose 3.5 ppm on sunny and hot days when we leave the cover off, or less than 0.5 ppm on cloudy days when the cover is left on. Since these days tend to string together in batches of 3 - 5 days of similar weather, that can be a total loss of 15 ppm versus 2 ppm, over the course of a few days. Long story short... I don't think there's any constant SWG setting that will allow me to ride from week to week.

My first few days running the SWG, FC went thru the roof, because the cover was always on. The last week, the cover has been off a lot, hence the lower readings. Still finding the settings that work best under each scenario.

 

[dereksanders]

I adjust my run time daily based on several factors. It takes very little time to figure the math and adjust. I’m out there daily already.

 

[Newdude]

Dare I say it's *fun* to figure it out once you have a grip on the basics ?

Pool #2 responded differently than the 1st and I was out there everyday taking mental notes laughing like a mad scientist.

 

[dereksanders]

My pool settled into its own routine. Had to add stabilizer twice and acid once. I only lost .5ppm FC today due to overcast conditions and no one in the pool. 9ppm at 05:00 and 8.5ppm at 15:30. Likely won’t have to run SWCG tomorrow but 1-2 hours.

 

[P00LNerd]

Dare I say it's *fun* to figure it out once you have a grip on the basics ?

Pool #2 responded differently than the 1st and I was out there everyday taking mental notes laughing like a mad scientist.

Definitely. Heck, between this SWCG and my automatic irrigation system, I just about don't know what to do with myself all day, anymore.