something is neutralizing my Cyanuric Acid

[jaydar]

I've just brought pool up to superchlorination. 2 days ago everything was in balance yesterday had become cloudy/milky.I couldn't get out to test yesterday.

Ph had been holding steady.

numbers now

FC- 16
CC- .5
TC- 16.5
PH - 7.5
TA- 100
Borates- 30
CYA- 30

It's got to have something to do with the HTH Super Algae guard.
I added 2 lbs dry cyanuric which brought my cya up tp 50 last week. It had fallen from 60 to 30.

Borates also went from 55 to 30.

I don't want to add anymore dry acid just in case there is a chemical interference with present tests.I know what a problem it is when cya gets too high.

I forgot to mention...my chlorine won't hold...this is 3rd time in 7 days I have found free chlorine at 0 and shocked it. So it's dropping 16 ppm in 2 days and that is with a couple of pucks in a floater.
Any suggestions?

 

[frogabog]

When you say shock, do you mean you add chlorine to shock level and then let it sit for two days expecting miracles?

If so, that sounds normal for it to go to 0. Shocking is a process, not a one time action. If you need to shock, there's something in the pool that eats chlorine, it will eat it right up if shock level is not maintained till the shocking process is complete.

Might want to brush up on shocking in pool school.

The CYA reading you are getting are odd. One would think if you added CYA a week ago, it'd show up. Are you very sure of your testing? There has been some discussion about ammonia neutralizing CYA recently, a search should pull up the threads.

 

[jaydar]

not usually...just had lumbar fusion surgery...hard to get around some days.

Normally I check pool every day...brush and vac

No miracles expected here.

If the reagen went bad maybe...but just bought it this spring....am familiar with how to do the test.
I'm thinking the algaecide is reacting with citric acid I used for metal stains....and then metal magic sequestrant.

But this happened before adding metal magic.

 

[JasonLion]

CYA doesn't usually go away unless FC has been zero for some time or there has been water replacement. In very rare cases CYA can go away if FC goes to zero for just a short time, but it is far more likely that there was some glitch in the CYA testing.

 

[JamesW]

Do you think that there is any chance of dilution? Perhaps a leak and an auto-fill?

 

[jaydar]

no..I'm not set up with auto fill.We've had some downpours over several days but not more than 2" rain.

I need to add some muriatic...about a pint but with my back surgery I'm weary about messing around with 5 gal bucket and mixing acid for the pour.

The only organics in the pool are some flowers falling from a nearby tree.

I've been running robot cleaner.....super shock cleared view to bottom and nothing is down there.

I tested water 4 hours later and had to add 32 oz bleach to bring shock back to 16.5 ppm.