CYA reading under 10 after 2 tests.

[bluetahoe]

I just posted this same issue on another thread and was told this is not unusual because the CYA does oxidize. Where ever we got the impression that it stays constant unless you have splash out or over flow is wrong and should be "updated".

I've always wondered this as well. Always seemed to me trichlor is not so bad as long as you keep an eye on cya and use only bleach to supplement chlorine levels, especially if you have a sand filter and backwash. If cya gets to the upper end of the recommended level, just stop using it and go to straight bleach until next year.

 

[borjis]

Ya definitely add half of what you think you need based on the test.
Usually when I add 1 lb of CYA it raises mine 10ppm, but sometimes it ends up being more like 20ppm.
And the test itself has an error rate of -+20 i think i read.

When I add via the sock in front of return, I go out and squish it about ten or twenty times every 15 minutes.
Makes my wrist sore, but I can dissolve 2 lbs completely within an hour doing it that way and test it
the next day.