Correct way out of balance levels

[anothernewpoolguy]

Oh, I should probably also mention that I have a small leak in the concrete. Another item to be addressed eventually.

 

[reggiehammond]

Your TA will cause pH rise, which necessitates acid additions. You won't change that fact.
You do need to worry about pH, it's not something you want to let hang at 8.0 for a long time.

The sooner your TA find equilibrium, the sooner your pH will remain steady. That's a good thing.
Calcium scale is avoided by maintaining proper pH and keeping an eye on CH levels and CSI.

In your situation, too low of CH with improper pH will cause calcium to be pulled from the plaster, not the CH going the other way.

If you have a leak - every gallon you lose is taking CH away, because your fill water is lower in CH than the water it's replacing.

 

[anothernewpoolguy]

Maybe I’m not stating the question well. I know what will happen with high TA and the recommended way to maintain a balanced CSI. Scaling won’t occur if CSI is in a good place, but a good CSI can be had even if TA is high and low CH (like how my water is now). My point is as I keep adding acid (to suppress the continually raising pH) and my TA drops, I’ll eventually need to add CH to keep a good CSI up. If one doesn’t want to add CH, the alternative way to keep CSI up would be to keep TA up. pH will always be maintained within the acceptable levels. The obvious down side is overall a lot more acid will be needed in this approach to maintain a good pH, vs the traditional approach of getting TA down so the upward pressure on pH is less.

My leak is a separate issue to the CH dropping thing because it’s very small and I have not topped off my water level since the initial filling.

 

[Mdragger88]

Maybe I’m not stating the question well. I know what will happen with high TA and the recommended way to maintain a balanced CSI. Scaling won’t occur if CSI is in a good place, but a good CSI can occur even if TA is high (like how my water is now). My point is as I keep adding acid and my TA drops, I’ll eventually need to add CH to keep a good CSI up. If one doesn’t want to add CH, the alternative to keeping CSI up would be to keep TA up. The obvious down side is overall a lot more acid will be needed in this approach to maintain a good pH.

My leak is a separate issue to the CH dropping thing because it’s very small and I have not topped off my water level since the initial filling.

In the long term your ch will rise as you will need to replace water lost to evaporation with calcium laden water. The calcium remains & doesn’t evaporate.
You will likely not need to add any significant amount of ch unless you exchange alot of water.

 

[anothernewpoolguy]

Yes. My issue is my TA is getting lowered right now (with the added acid in order to keep pH in range) and I’ll quickly be at a point where I’ll have to add CH to keep CSI up. I’d rather keep CH low now while I can, and as summer comes and fill water adds CH, then the TA can be maintained at a lower level.

I’m just trying to avoid adding CH artificially now. My fill water has high TA (140ppm) so when the time comes to fill, that will add some additional upward pressure on CSI.

 

[reggiehammond]

CSI can be 0.6 to -0.6 with ideal being -.3 to 0.3. As your water warms up, your CH level will not cause CSI issues.
Your high TA and high TA fill water will certainly cause pH problems though, so I'm not sure what you're trying to gain.

Play with the CSI calculation inside the CSI tab in pool math results.

 

[anothernewpoolguy]

My current numbers:

pH: 7.6
TA: 110
CH: 230
CYA: 45
Avg temp: 55F
CSI: -0.26

My pH has been rising fairly quickly so I've been pushing it down with acid, which in turn is rapidly dropping TA. This is further pushing my CSI more negative. For example, if this continues and TA eventually gets to say 80, the CSI (all other levels the same) goes to -0.42. The only other levers to bring CSI up is increased water temperature and increased CH. At the pace I've been adding acid, the water temp isn't going to go up significantly by summer to match. That leaves CH as the sole lever. So either I increase CH as that happens, or ignore it and live with decently negative CSI until (hopefully) summer. Maybe being CSI negative for that short of a time is irrelevant. CSI before I refilled was massively negative for years.

 

[Mdragger88]

As the ta gets lower you won’t be needing to add acid as frequently most likely. Don’t worry so much about what may happen in the future & try to plan it so precisely. Keep going like you are now & it will work out.

 

[reggiehammond]

My current numbers:

pH: 7.6
TA: 110
CH: 230
CYA: 45
Avg temp: 55F
CSI: -0.26

My pH has been rising fairly quickly so I've been pushing it down with acid, which in turn is rapidly dropping TA. This is further pushing my CSI more negative. For example, if this continues and TA eventually gets to say 80, the CSI (all other levels the same) goes to -0.42. The only other levers to bring CSI up is increased water temperature and increased CH. At the pace I've been adding acid, the water temp isn't going to go up significantly by summer to match. That leaves CH as the sole lever. So either I increase CH as that happens, or ignore it and live with decently negative CSI until (hopefully) summer. Maybe being CSI negative for that short of a time is irrelevant. CSI before I refilled was massively negative for years.

Play with temperature in the CSI calculation.. values will change a lot given how cold you currently report the water temperature.

CYA is also not valid at 45. It's either 40 or it's 50.

 

[anothernewpoolguy]

I have a full time water temp data logger. It fluctuates day/night between 50F-58F. My pool is mostly shaded. I'd guess at peak summer (July/Aug) it could add 10F, but that's just a guess.

How is 45 not a valid number for CYA? The Taylor tic marks are at 40 and 50, but the scale (slightly logarithmic) is easy enough to see where 45 is.

 

[Mdragger88]

I have a full time water temp data logger. It fluctuates day/night between 50F-58F. My pool is mostly shaded. I'd guess at peak summer (July/Aug) it could add 10F, but that's just a guess.

How is 45 not a valid number for CYA? The Taylor tic marks are at 40 and 50, but the scale (slightly logarithmic) is easy enough to see where 45 is.

45 counts as 50 for chlorination purposes.

As mentioned in CYA Testing - Further Reading
“The spacing between the lines on CYA viewing tubes varies and is not linear. With all the uncertainties in this test don't bother trying to interpolate between the lines on the test tube, always round up to the previous line.

If you saw the dot at 40 and not at 30 then you call it 40.

The tolerance/accuracy of the CYA test is about +/-15ppm or so, and it will not read below 20ppm, because of the limited solubility of the melamine-cyanurate complex.

Even if you could accurately state a specific value on the scale of the viewing tube, it is only a guess without calibrated markings. With TFP methods there is no reason to squint, stress, or guess at values on the CYA tube. See between what lines the dot disappears and round up and you have your CYA value within the accuracy of the test.”

 

[reggiehammond]

I have a full time water temp data logger. It fluctuates day/night between 50F-58F. My pool is mostly shaded. I'd guess at peak summer (July/Aug) it could add 10F, but that's just a guess.

Ok good - sounds like you've got the idea and have things in control. You also have one very cold pool!

 

[anothernewpoolguy]

I wanted to report an update mid/late pool season. Thanks to this site and everyone's comments here, everything going well with the pool. Chemistry is stabilized and have been monitoring/adjusting as needed.

Been testing daily with the Taylor kit to see any trends. No surprises there. I've also been using AquaChek 7 strips to see how it stacks up. I don't depend on the readings other than FC, which has been reporting levels pretty close to the Taylor. TC has also been reasonably close, but the green color levels are harder to tell apart compared with the purple levels the FC uses. I might still buy these for the more frequent FC checks, and depend on the Taylor for precise FC, any problems, and getting readings on other chem levels.

It did appear I had something uptaking the calcium I kept adding. I suspect it was walls and other locations that had been etched/starved of CH from years of way too low pH levels. That has stopped and CH has stayed stable with just a very slight upward climb due to evaporation/refilling. Even though we've had some hot periods, I suspect the CH climb hasn't been an issue for me because it's mostly shaded, pool temp tends to stay on the cool side (reduced evaporation), and splash out has been high due to crazy kids and heavy in/out usage (so the high CH water goes out while low CH fill water goes in).

I kept using the trichlor pucks (since I already had them) until my CYA level got to where I wanted, somewhere between 40 and maybe 50. CYA has remained relatively stable but I think I could be using the pucks more than most people due to the splash out and a minor leak I still have.

Still been battling with high'ish TA levels, which keeps me adding acid to keep pH down. I suspect due to the heavy aeration action from users, my wall cleaning robot, and the refill water which is high in TA. Wish this didn't need monitoring, but it is what it is. It hasn't been that terrible to stay on top of.

My skimmer basket has been occasionally floating up letting leaves through to collect at the pump pre-filter. I couldn't figure out what people normally do to address that, so I just bought this 316 stainless ring to put at the bottom of basket:

Amazon.com

It's large enough that even if it fell out of the basket, it wouldn't obstruct the pump's suction port. It's arriving today so can let people know how it works (or not) if interested.

I'll likely be switching to a SWC generator this year or next. Both for the convenience but also the issue of me being away from the pool for long periods and having to depend on friends to FC dose while away. This switch will also include me swapping out the pump to a variable rate with some scheduling/smart controls.

Thanks everyone for the feedback. Pool is tip top and been getting heavy use this season.

 

[wireform]

 

[dereksanders]

I’m trying figure out a way to keep my skimmer basket in place, too. At close to a pound it may do the trick. I’m curious to know if it works out for you.

 

[generessler]

My skimmer basket has been occasionally floating up letting leaves through to collect at the pump pre-filter. I couldn't figure out what people normally do to address that, so I just bought this 316 stainless ring to put at the bottom of basket:

The ring looks like the Cadillac solution. Beautiful. I think most here use a clean rock. Important caveat: Make sure it's big enough that it can't possibly go down the suction pipe. There's an epic thread where that happened, followed by a heroic effort to get it un-jammed.

 

[anothernewpoolguy]

The ring's inner diameter is 4" and is 1/2" thick. It's definitely not getting through the suction port. I might have wanted a little more weight, but it feels hefty enough to hold the basket down.

Edit: meant to say 4” inner diameter. Fits perfectly at bottom of basket.

 

[pjt]

My skimmer basket has been occasionally floating up letting leaves through to collect at the pump pre-filter. I couldn't figure out what people normally do to address that

Just put a rock in the skimmer basket. Make sure it's larger than the suction pipe at the bottom of the skimmer.