Is CYA always this weird?

[dogsbody]

I'm still working on getting the numbers in place after a purge+refill. Knocked down the TA as predicted.
Got the pH into a good place. Upped the CH. Life was good. But I couldn't get the CYA to register - I
added small (30gm) doses every couple of days, but just couldn't get it to budge over the 30ppm
threshold. So I gave it a little extra (50gm), and next thing I knew I was reading 100ppm. I mean, the
disappearing-spot test scale is logarithmic, but does it behave this nonlinearly when adding CYA as well?

So I'm somewhat over the recommended-max of 60. It's cold here, so we keep it covered when we're
not in it, so no UV degradation. I really don't want to have to dump+dilute and have to adjust everything
all over again. Will I be okay at 100?

 

[ajw22]

CYA can take a few days to dissolve and show up in the test.

We recommend you use PoolMath Effects of Adding and calculate the effect of what you added and assume it will show up in tests after a while.

You do not have anything in your signature indicating how you chlorinate your pool. So hard to say what you should do about your CYA 100.

Do the dilution test to comfirm your CYA is not higher…

For CYA > 90ppm, repeat the test, adjusting the procedure as follows:

1. Fill the mixing bottle with pool water to the lower mark (15 ml line).
2. Continue filling the mixing bottle with tap water to the upper mark (30 ml line).
3. Shake briefly to mix.
4. Pour off half of the contents of the mixing bottle so it is again filled to the lower mark (15 ml line).
5. Continue the test normally by adding R-0013, but multiply the final result by two.

If you need to dilute the pool water further, then apply these ratios:

Pool water	Tap or distilled water	Multiply result by
1	1	2
1	2	3
1	4	5

Note that when doing a diluted test, you multiply the range of the test and the error rate of the test, so the results are a ballpark—not an absolute.

See CYA Testing for tips on how to read the test results.

 

[Gebo]

I messed up by daily adding Dichlor to get my CYA up. I, like you, have learned to wait a few days as the CYA "release" is a really delayed reaction. Next fill I will be a lot more patient as I raise my CYA with Dichlor.

 

[dogsbody]

CYA can take a few days to dissolve and show up in the test.

We recommend you use PoolMath Effects of Adding and calculate the effect of what you added and assume it will show up in tests after a while.

I don't carry a tracking device, but was using the web version. I suspect I didn't wait long enough before that last addition.

You do not have anything in your signature indicating how you chlorinate your pool. So hard to say what you should do about your CYA 100.

I'm using granular dichlor. I hadn't added any liquid bleach yet.

Do the dilution test to comfirm your CYA is not higher…

Sure, I understand the dilution series, but am really trying to avoid that at the moment, as it's -30 here.

So my initial question was: What's the downside of elevated CYA?

 

[dereksanders]

Down side of elevated CYA is you have to keep your FC elevated to be effective. At some point it becomes prohibitive along several avenues.

 

[dogsbody]

Thanks - I'm sure I read that but it hasn't soaked in yet.

1. Fill the mixing bottle with pool water to the lower mark (15 ml line).
2. Continue filling the mixing bottle with tap water to the upper mark (30 ml line).
3. Shake briefly to mix.
4. Pour off half of the contents of the mixing bottle so it is again filled to the lower mark (15 ml line).
5. Continue the test normally by adding R-0013, but multiply the final result by two.

Incidentally, my Taylor kit has a 14ml mixing bottle, not a 30ml. Even so, eight tests eats an entire (kit) bottle of R-0013, and for me restocking is a logistical nuisance - if I'd known it was consumed at a rate so disproportionate to all the other reagents, I would have bought a big bottle when I first got the kit.

 

[ajw22]

Incidentally, my Taylor kit has a 14ml mixing bottle, not a 30ml.

That is why we ask you to complete your signature with details of your pool, spa, and equipment instead of “Just the guy who does the thing.” so we can give more specific advice.

Even so, eight tests eats an entire (kit) bottle of R-0013, and for me restocking is a logistical nuisance - if I'd known it was consumed at a rate so disproportionate to all the other reagents, I would have bought a big bottle when I first got the kit.

What model Taylor kit do you have? We recommend the K-2006C since it has larger reagents.

 

[dogsbody]

I bought the K-2006C for just that reason, and it contains three 2oz bottles of the CYA reagent. But even with the smaller mixing bottle, at 7ml/test it gets burned down at a much higher rate than all the (per-drop) others.

 

[Mdragger88]

after doing the diluted cya test to confirm your actual cya level follow the
FC/CYA Levels with liquid chlorine until you can replace some of your water with fresh to get your cya down.
If you keep your tub quite hot 100+ F
you may lose a little cya via degradation but not much.
If you have a problem- like cloudiness or persistent cc’s you’ll need to dilute your water to lower cya as slam/shock at that cya level is hard to accomplish.

 

[Bperry]

Thanks - I'm sure I read that but it hasn't soaked in yet.



Incidentally, my Taylor kit has a 14ml mixing bottle, not a 30ml. Even so, eight tests eats an entire (kit) bottle of R-0013, and for me restocking is a logistical nuisance - if I'd known it was consumed at a rate so disproportionate to all the other reagents, I would have bought a big bottle when I first got the kit.

Side note, if you add CYA to a skimmer or other water intake, the granular CYA can get trapped in the filter and take a few days to dissolve. Ignore any instructions on the product to do that.