Observations on my pools CYA changes and using test kit standard to confirm reading

[NSBFAN]

Hey all. I started doing the TFP method back in November. Prior, the pool was maintained weekly by a service. Trichlor pucks were used then and when I started, the CYA was well over 100. Via Taylor kit and 1/2 dilution, the best I could estimate was130-150. Since I was not going to use the pool for the winter season, nor heat it, I decided to forgo a major drain and refill. I drained down a little bit a couple times due to rainfall fill but not much.

When I started up the pool in March, I found that my CYA was about 80 - 90. Didn't need dilution but after doing the test a few times you can see how cloudy. So I decided to leave it there and keep my FC around 8-9 which required about 1-2 pints of 10% each day once the pool temp got to 86 degrees. The pool doesn't get heavy use - just my wife and I each day for an hour or two.

I decided to check CYA again and saw it was around 40-50! I ordered the standard and verified. Even without that, I could see it was much less cloudy than in March. I only drained about 2 inches of water off the pool once due to rain and in the spring had to add some water. But I always read that CYA won't evaporate out. But it obviously does go down. We don't have splash out.

Anyway I found it interesting and thought I'd share. I'm glad I know I am able to get a somewhat reliable CYA reading.

My latest pool numbers:
FC - 6.2
CC - 0
TA - 70
PH - 7.6
CH - 310
Borates - 30-40
CYA - 45

 

[kimkats]

I am not sure where it goes but mine goes bye-bye also. I really think it is all of the rain we get here in FL. I am forever having to lower my pool due to the rain. I am thinking we exchange a lot more water than we think we do.

I am going to get some pucks this week as we are going out of town in a week or so. I love that I have the CYA wiggle room to use them!

Kim:cat:

 

[needsajet]

CYA degradation is complex and I need an extra head that doesn't spin around, just to read about it.

The main takeaways for me are: 1) CYA can't go up on it's own, and 2) get good at the test, test monthly, trust the test, and adjust CYA accordingly.

If you like reading stuff that makes you feel like today would have been a good day to skip school... Degradation of Cyanuric Acid (CYA))

 

[NSBFAN]

Yes Kim I hear you. This year the rain hasn't been as crazy as years past. I only had one event that caused me to drain a bit off. I'm glad too to have the room as I like using the pucks when I am gone for a few days.

Needsajet - that is some heady stuff. Your takeaways are great. Thanks.