Switching from Frog to SWCG

[P00LNerd]

Disregard the silver and copper in the water for chemical balancing purposes.
Use the FC/CYA Levels chart and keep FC near the top of the target range for your CYA lefel.
Use PoolMath to determine dosage.

Your pool is still a non-SWG pool. For CYA 50, minimum FC is 4 and target is 6-8.
Minimum is like a cliff - stay far away so you don't fall off. Dose for high side of target.

Okay, I'll work up to that. I guess the reason I was resistant is that I've had FC at 3.5% - 5.5% of CYA for more than a year, with zero issues. I know now that's because of the copper and silver in the water, but they're not going away anytime soon.

Oh, and since I'm manually dosing, do we aim to keep fall-off above 4 ppm? As in dose up to 6-8 in the evening, and make sure it doesn't fall below 4 during the subsequent day?

For "SI", are you using LSI or CSI? List the full acronym, not just "SI".
Suggest you use CSI, as it's in PoolMath and keeps us all on the same page.

Hah... sorry. I can never remember. I'm using the Taylor blue Watergram decoder wheel, and it's just labeled "saturation index". No L or C, whatever they are. If my memory is correct, even the equation in the accompanying booklet is just "SI", no "LSI" or "CSI" distinction.

Continue to use the sequestering agent for now.
The silver and copper will remain in the pool until removed via draining.
Water exchange can happen another time, if it's needed.

No problem. Any advice on getting rid of the shadow staining forming above water line? I'm figuring either put LC or sequestering agent in a bucket, diluting with a bit of water, and scrubbing with that?

 

[Newdude]

. I guess the reason I was resistant is that I've had FC at 3.5% - 5.5% of CYA for more than a year, with zero issues. I know now that's because of the copper and silver in the water, but they're not going away anytime soon

You should continue with little FC loss because of your yard/shade. The copper and silver do nothing for your daily UV loss, which on a sanitary pool, is the overwhelming bulk of FC loss. If your yard dumps organic crud in the pool at times, that'll happen either way and again the chlorine gets it long before the copper and silver.

When there no algae, no FC is lost to it. Bacteria/viruses and such don't consume enough to notice, and residential swimmer load is minimal at most. Yes I have a large pool, but we had 2 families of 5 over at the old place at least once a week and with 14 swimmers (most of them little) I rarely saw any substantial losses. 1 or 2 FC tops. We also had 2 giant dogs who swam and the FC loss was mostly constant regardless if we were using the pool or not.

Moving up the block from a mostly shaded yard to a wide open one almost doubled my daily losses, and we don't have little kid swim parties anymore. Your battle is with the sun once you're sanitary and as long as you stay free and clear from minimum FC, will continue to be your only battle.

 

[P00LNerd]

You should continue with little FC loss because of your yard/shade. The copper and silver do nothing for your daily UV loss, which on a sanitary pool, is the overwhelming bulk of FC loss. If your yard dumps organic crud in the pool at times, that'll happen either way and again the chlorine gets it long before the copper and silver.

Cool. I actually get full sun through the whole middle of the day, as the pool is in a relative clearing in the trees that dot our yard. I'd guess it's full sun maybe 10am - 5pm, but mostly shaded by house or surrounding trees outside of those hours.

We get leaves regularly blowing in, as our trees are mature and large. Most of those leaves are coming from a cluster of trees 100 feet or more from the pool, just carried by the wind. Also, a lot of spring pollens, all of which I guess the FC must battle.

Swimmer load is usually low, only two kids, middle school and high school. Because of cool weather and travel, no one has been in the pool at all the last two weeks, although we have two teenage pool parties scheduled for this weekend.

In the past, I'd have done a non-chlor shock (Oxy Out) after a weekend like this, with ten or a dozen kids using the pool over two days. I guess that goes against TFP guidelines?

 

[Newdude]

I guess that goes against TFP guidelines?

MPS / non chlorine shock messes your readings up for a while so it's counterproductive.

We raise the FC enough before a get together and then check after to ensure there's still a buffer. I go to half slam for medium get togethers and full slam for blowout parties.

 

[P00LNerd]

Before? Really? That goes so much against my intuition, in terms of bather comfort. I'm used to shocking after events.

I just added 84 oz. of 10% Cl, per Pool Math. I can't help but think everyone's eyes will be burning this afternoon, or that we're going to have some bleached bathing suits and towels. I'm used to never seeing FC much above 2 - 3 ppm.

This is a whole new world, for me.

 

[Newdude]

This is a whole new world, for me.

It's been road tested and fine tuned for 17(?) years by hundreds of thousands of folks before you.

 

[SJPoe]

My pool generally sits at about 9-10ppm FC, with a CYA of 80. The only comments I ever get is how my pool doesn't smell like chlorine, and how people don't get sore eyes or anything.

As long as your FC and CYA are in balance, there will be no impact to your bathers.

If you want to get into the reasons why, there are some far more detailed discussion posts available in the forum that explain the role of CYA, Hypochlorite ions and so on...

 

[proavia]

Hah... sorry. I can never remember. I'm using the Taylor blue Watergram decoder wheel, and it's just labeled "saturation index". No L or C, whatever they are. If my memory is correct, even the equation in the accompanying booklet is just "SI", no "LSI" or "CSI" distinction.

Just use PoolMath. It automatically computes CSI. No need to mess with that water wheel anymore. And you will save time as well.
Again, allows us all to be on the same page.

Always dose to the high end of target range or higher BEFORE a swim event. And if it's a long event with lots of kids, dose mid way thru amd again at the end.
Stay away from non-chlorine shock products.

 

[P00LNerd]

Just use PoolMath. It automatically computes CSI. No need to mess with that water wheel anymore. And you will save time as well.
Again, allows us all to be on the same page.

I just entered this morning's data, first time I figured out how to log data, rather than just using instant feedback. But for some reason, I'm not finding anywhere the app reports LSI or CSI.

Stay away from non-chlorine shock products.

Dang... I'm going to have some stuff to sell or trash, when this is all done. I think I have a fresh 3 gal (25 lb.?) bucket full of non-chlor shock in the cubboard, among other things!

 

[proavia]

In PoolMath
Click gear icon
Scroll down to tracking
Turn on CSI, CC, Water temperature, Salt
AND
Scroll down to sharing
Turn on Link from.... so your PM logs show to your forum account.
PM email and password need to be the same as your forum account.

 

[P00LNerd]

In PoolMath
Click gear icon
Scroll down to tracking
Turn on CSI, CC, Water temperature, Salt

Hah... was just headed back here to post I found it. You stole my thunder!

Result is 0.10, which I guess seems good.

One thing that always frustrates me with pool test goals, aside from all the conflicting advice out there, is the use of ranges rather than targets. Sure, knowing an allowable min-max is useful, in determining the urgency of fixing a given parameter drift. But honestly... it's pretty darn easy to hit a target better than our ability to measure it. Using a range for FC makes sense, as it changes by the hour, but I'm pretty certain I could hit a ±0.10 target on pH, TA, and CYA with very little math and effort, at least when working fresh water up from below target. Give me an ideal target, not a range of "good enough"!

 

[PoolStored]

Turn CSI off, it doesn't matter in a Vinyl pool.

 

[proavia]

Goal is to keep CSI in the 0.00 to -0.30 (negative 0.30) range to minimize scalimg in the SWG.
With your vinyl liner, even more negative is fine as well - as you aren't needing to find a balance to minimize scaling AND protect the plaster pool surface.

Try to stay away from other sources - most all are using decades old advice and are NOT based on science.
Target ranges are more practicle. A pool exposed to the environment is always changing.

As for the +/- 0.10 - good luck with that. You will spend more time trying to hit that target than you will actually spend enjoying your pool. Remember, we aren't making rocket fuel here - most times close is close enough.

 

[proavia]

Turn CSI off, it doesn't matter in a Vinyl pool.

He's going to install a SWG. Better he knows he is at least slightly negative to minimize SWG scaling.

 

[PoolStored]

Goal is to keep CSI in the 0.00 to -0.30 (negative 0.30) range to minimize scalimg in the SWG.

He lives in PA. Fill water here is low CH. Unless he adds CH, which he should not, his CH will remain low and a high CSI is not typical in these parts with typical rain and winter snow...

 

[Newdude]

I've had a -.9 to -2.0 CSI since 2012. You'll be fine.

 

[proavia]

He lives in PA. Fill water here is low CH. Unless he adds CH, which he should not, his CH will remain low and a high CSI is not typical in these parts with typical rain and winter snow...

OP: "Result is 0.10, which I guess seems good."

 

[P00LNerd]

He lives in PA. Fill water here is low CH. Unless he adds CH, which he should not, his CH will remain low and a high CSI is not typical in these parts with typical rain and winter snow...

My normal fill water is around TH = 260 ppm, but I have an option to use softened water, if I want to go to the trouble to drag a few hundred feet of hose from my garage to the pool.

Presently, I'm running around CH = 110 ppm. I'll make some time to test the fill water for CH later today.

 

[TinFoilHat]

Also, the higher ppm of chlorine won't give off an odor unless it's reacting with organics in the pool. So if you have the pool clear of algae then you shouldn't smell the chlorine.

 

[SJPoe]

Hah... was just headed back here to post I found it. You stole my thunder!

Result is 0.10, which I guess seems good.

One thing that always frustrates me with pool test goals, aside from all the conflicting advice out there, is the use of ranges rather than targets. Sure, knowing an allowable min-max is useful, in determining the urgency of fixing a given parameter drift. But honestly... it's pretty darn easy to hit a target better than our ability to measure it. Using a range for FC makes sense, as it changes by the hour, but I'm pretty certain I could hit a ±0.10 target on pH, TA, and CYA with very little math and effort, at least when working fresh water up from below target. Give me an ideal target, not a range of "good enough"!

But in essence, a range IS good enough. The CYA/FC balance means you don't have to be managing your FC to 0.1ppm resolution...

PH/TA/CYA will remain fairly stable. PH/TA is going to vary based on the type of pool, your fill water, whether it rained last night, how much aeration is occurring, etc etc - the bottom line is that they are not going to SIGNIFICANTLY impact your water quality unless you are in a Plaster/Gunite pool, and you're way out of range. As long as they are balanced, your plaster pool won't scale or erode. Likewise with your SWG plates - as long as they are within reason, you'll be fine.

CYA is also fairly stable, and you can aim for a specific value - but the test is fairly subjective, so +/- 10ppm is about a good as you get. As this drives the FC number, having some 'wiggle room' on the FC makes sense.
Depending on the time of day, the specific location in the pool, and other variables, your FC number could fluctuate significantly - so providing a target range reduces the panic-induced lobbing in of chemicals to solve a perceived problem that doesn't exist.

If your PH/TA/CYA/FC are within the ranges suggested, you'll have no problems. Trying to aim for a specific number just means you'll be chasing the needle all the time...not 'Trouble Free'