CYA Through the Roof, About to Try to Deal With it.

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OK, another 4,000 gallons pumped out and replaced yesterday. I had to order more CYA reagent which arrived today (got smart and ordered the 16 oz bottle) and I just tested the pool and doing a 1:1 dilution shows the CYA levels are now down to 160. MAN they must have been astronomical to begin with. The pool calculator show that the target FC level for a CYA this high is 11-18, and I've got it right at 12.5 now. Even as out-of-whack as this still is, I can already tell things are getting much better. I've had a little bit of algae trying to get restarted on the walls the last week or so, and it's going away now. I actually swam for a little bit today.

Things aren't right yet, but I'm on the right track.
 
We're now on the third iteration of "See Ya, CYA." Put my trusty pump to work this morning, now the garden hoses are hard at work refilling. This time should get me down around 100ppm CYA... sigh. Picked up some more Clorox at Sam's Club this morning - a 3 jug package of 8.25% for $8.18, about the best price I've found around here.
 
I took over my pool with CYA up in the 220-240 region and we were under strict water restrictions at the time, so I couldn't drain. Be grateful. Now that my CYA is down in the 50 region, it's so much easier to maintain. It's a PITA, but it will be so worth it. By next weekend, I suspect your pool will be sparkling, odor-free, and non-irritating, and people will actually see it and say, "Ooh!"
 
Wow that CYA is high. Keep going and may I say you have nice green grass! :mrgreen:
 
Casey said:
Wow that CYA is high. Keep going and may I say you have nice green grass! :mrgreen:
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It certainly is now - I've put about 12,000 gallons of water on it in the last week ;)

One thing I forgot to mention is that when I took ownership of this pool about a year ago, the pH was 4.6. Yep, that's right, four point six. I had to borrow an expensive field pH meter from the aquatic biology lab at work to even measure it. If I'd known what I know now, I'd have instantly realized what was going on. Man, the Trichlor tablet market is a racket.

Also I'd been running my pump 12 hours a day or more to try to keep enough Trichlor in the water, now that I'm using liquid chlorine I can undoubtedly cut that run time way back.
 

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Sorry, but your math isnt right. 1:1 you multiply by 2, 1:2 you multiply by 4 if your indicator showed 70 then the estimated is 280 ppm. If you're dumping half the diluted water then diluting again then dumping half of that then adding your reagent
 
timerguy said:
1:2 you multiply by 4
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1:2 is 1 part sample, 2 parts diluent. Which means the original sample is 1/3 of the total volume, so you multiply by 3.

Let's prove that with simple math:

Say you have a sample that contains a known volume of any particular analyte. Since we're talking about a multiple of three, let's make it easy and say it's 90 mg/l. "Parts per million," or "ppm" is a less precise way of expressing that concentration.

So if you have exactly 90 mg of analyte in 1 liter of water, that mass does does not change. If you add 2 liters of dilution water (water that is free of the analyte of interest) to that, there is still only 90 mg of analyte, but now it's in 3 liters of water. The concentration is now 30 mg/l.

If you want to correct that back to the original volume, you multiply 30 mg/l x 3 = 90 mg/l.
 
I realize this is not a poll but if it were my vote would be for Pflugerpool's math.

1:1 - x2
1:2 - x3
1:3 - x4

That said...

timerguy said:
If you're dumping half the diluted water then diluting again then dumping half of that then adding your reagent
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... IF you did what timerguy described (dilute 1:1, then dump half, then dilute 1:1 again, then dump half, then add reagent), which I don`t *think* you did but not 100% sure, then you would actually be diluting 1:3 so quadrupling would be correct:

Start at 90 ppm, dilute 1:1 gives 45 ppm
dump half, dilute 1:1 gives 22.5 ppm
dump half, add reagent, multiply result by 4 to get 90ppm

Everyone a winner !
 
Further, that's how the operation is described in the extended text kit directions.
1:fill with sample to the bottom line.
2: dilute to top line with tap water. Shake to mix
3: dump to bottom line
4: add reagent to top line
5: drop slowly into into measurement tube multiply by 2
Now here's what actually happened:
1: performed initial cya test per instructions, didn't see black dot--emptied the test vial
1-5: never did see the black dot-- Leslies had been telling me my cya was only 40-- emptied the test vial
Steps 1-3, steps 2-5(2 dilutions)- still no black dot! Oh ohhh, now what! Emptied test vial
Steps 1-3, steps 2-5(2nd dilution)steps 2-5 (3rd dilution)- finally a black dot! Measured 85ppm multiplied by 4 = ~350
What we really need is a procedure to reuse the the reagented sample diluted as often as necessary to get the black dot visible! There had to be some way to do that! I my case, I had wasted 28ml of reagent. I had also bought a 16 oz bottle. I had already gone though both .75 oz bottles that came with my kit and and 2 oz bottle bought from leslies that cost me more than what I paid for the pint bottle. I still have a little over half of it left.
 
robl45 said:
you are taking out water, adding new water, then draining that water out again, it would be best to take out as much as you can at once, otherwise your not getting the full benefit.
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In my case I don't have a lot of choice. I'm on septic, so I don't have city sewer to drain to. I have to put the water out on the grass, and I've only got so much area I can drench with water at one time without it becoming a big muddy swamp. I'm pretty much having to do it stages, and yes I realize that there are diminishing returns since I lose some of my new water each time.
 
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