Is it worth it having a high cya?

[Mickey Moose]

Data is both beautiful and mischievous. I am getting an idea now of how this works (I think) and am looking at both the red "additions in oz" of the first graph and the blue "FC in ppm" in the second graph and assume the data points represent the same day on the X axis correct? If so then this should a reflect a ppm FC response from your Cl applications. For example take the 1st data point in the top graph (155oz addition), now which data point on the bottom graph FC blue line is the response to the chlorine addition and how much time elapsed? Any way you can add a second Y axis and expand the FCppm data range from 1-7 over the top of your oz of additions range 20-180?

Keep the cat in the bag if you can.

Yes, the charts are from the same time periods - today, going back 30 days. The oldest tests are at the left. So the oldest test, where you asked about adding 155 oz, my FC was 3 (first blue point on 2nd chart) that day and given my Target FC 7 that means my FC loss was 4 (first red point on 2nd chart).

I have a solid track record of testing everyday - so from point to point is "24 hours" (not exactly of course, but pretty close). Occasionally I miss a day here and there or even consecutive days in the case of business travel or vacation. But, in the charts you've seen - previous 30 days - I didn't miss a single day of testing.

I've toyed around with multiple Ys and may add that as an option but based on how I've built things to this point it's a bit of work and since it's only me it's not a big deal to not have it in contrast to it being easier to optionally change from actual values to percents and to optionally have log scales.

 

[Oly]

OK thanks. Data dedication, very impressive.

So is your FC test on a given day before your chlorine addition on that day? Also is your target FC number a pool math projection or an actual test number say an hour or overnight after the application? I may be going out on a limb here but if your target FC number is assumed then your FC loss is also an assumption correct? This may account for, or at minimum affect the FC fluctuations not due to increased bio-load. There have been several reports of the degradation of bleach % that make it difficult to rely on assumed concentrations and require at least periodic testing to verify the input and confirm the model. I like testing FC overnight after an evening application at minimum and once a week or two I observe the overnight chlorine loss and to exclude any FC loss to sun exposre I will test 1 hour after an app and compare to an the early AM test to track FC.

Biological systems are fascinating and the ability to accurately model them to be able to make predictions about future trends, priceless.

 

[Mickey Moose]

OK thanks. Data dedication, very impressive.

So is your FC test on a given day before your chlorine addition on that day? Also is your target FC number a pool math projection or an actual test number say an hour or overnight after the application? I may be going out on a limb here but if your target FC number is assumed then your FC loss is also an assumption correct? This may account for, or at minimum affect the FC fluctuations not due to increased bio-load. There have been several reports of the degradation of bleach % that make it difficult to rely on assumed concentrations and require at least periodic testing to verify the input and confirm the model. I like testing FC overnight after an evening application at minimum and once a week or two I observe the overnight chlorine loss and to exclude any FC loss to sun exposre I will test 1 hour after an app and compare to an the early AM test to track FC.

Biological systems are fascinating and the ability to accurately model them to be able to make predictions about future trends, priceless.

The FC values you see are before adding bleach. Target FC is based on CYA (see Pool School - Chlorine / CYA Chart), currently 40 for me.

I tend to [need to] use the high value of the Target FC range. My FC loss is an actual calculation of the "assumed" FC (again, based on CYA) minus FC. Example, with Target FC 7 and measured FC 4, FC loss is 3. The bleach added vs FC chart (or bleach added vs FC loss chart) shows that FC (or FC loss) almost always jives with bleach added. Though these won't necessarily be exact, the different views reinforce each other. Another chart I use is FC versus FC minimum (see previous link)... minimum is currently 3 for me which only two of the previous 30 days have I dropped below... both times, if I recall correctly, after big parties which makes sense. On occasion, maybe every week or so, I verify FC about an hour after dosing. I always measure and dose in the evening. Never have I verified FC in the morning - not a morning person.

The irony of this is that I make *trouble* free pool way more *trouble* than it's worth! I could simply use the knowledge of the approach and do nothing more and my pool would be no better or worse than with the mass amount of data I collect and can analyze. But I can't stop myself.