Mid Summer test results + clear water in CYA tests

Rockstead

Well-known member
Sep 2, 2010
476
Montreal, QC, Canada
Pool Size
100000
Surface
Vinyl
Chlorine
Salt Water Generator
I'm located in Montreal, swim season runs from Mayish until Early to Mid September with the Heater on.

Aside from my opening after the winter in May, I really haven't had to do anything but adjust the Chlorinator percentage, I did have my chlorinator level too low for during periods of rain and for the first time ever I had Algae outside the opening, a shock of FC 13 cleared everything up rather quickly.

I just did my second full test of the season apart from the opening and here are my results.

Based on my results I'm pretty suprised how spot on they are considering I haven't had to do or add anything after two months of running.

TA = 90
FC = 5.5, this is with my Chlorinato set to 50%, I have since brought it down to 40% to reduce my Chlorine down closer to 3 as my target.
PH = between 7.5 and 7.8
CC=0
CYA=? At opening I added enough to bring it to 50ish but I never tested it again becuase it was during shock time, the initial reading was 0 or clear after winter.

So I just tested it again and to my suprise the water is clear so no matter how much water I add to the tube with the black dot, I still see the black dot, so unless it is a matter of me understand the test, I'm not sure how it is possible all my CYA could be gone already or what to do next.

Based on that should I adjust anything, my TA is 10PPM too high but can I just leave it?

Next thing to try is adding DE to my sand filter for the first time.


Thanks everyone!
 
Don't worry about TA, that is close enough.

The CYA level is a bit more confounding. If you actually have a measurable FC level while the sun is shining on the pool, it is not really possible for that test result to be correct.
 
JasonLion said:
Don't worry about TA, that is close enough.

The CYA level is a bit more confounding. If you actually have a measurable FC level while the sun is shining on the pool, it is not really possible for that test result to be correct.

I guess it is my understanding on that black dot, I mean I can always see it, are you tellingme the water would be so cloudy that I really couldn't see the black dot at all, I don't see how that would be possible unless the water in the tube was a very dark colour.
 
When the CYA level is 20 or higher the water gets very cloudy, such that you can't see any hint of the black dot at all when there is enough water in the view tube. The cloudiness is white, and looks either white or light gray when you look at it.
 
JasonLion said:
Don't worry about TA, that is close enough.

The CYA level is a bit more confounding. If you actually have a measurable FC level while the sun is shining on the pool, it is not really possible for that test result to be correct.

I brought my chlrinator down to 40% over the past two days which were very hot and sunny and we used it frequently and I was able to bring the FC down to 4.5. I'm going to try reducing it to 30% to see if I can bringit closer to 3.5%, I figure my salt cell will last longer or less irritation to the eyes with less chlorine while still maintaining a recommended level, I don't know if I'm assuming incorrectly on those assumptions.

I took my measurements after a day of 6 people swimming at around 17:00, it was still very hot and sunny outside, I don't know why I have so much trouble getting a CYA reading, but maybe based on that I can assume my CYA is at a correct level seeing as though there is Chlorine in the pool.
 
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