Lost - Always 2.5ppm CC

[st12]

Apparently I can't get into my old account. Anyway...

Been fighting for weeks. 200 gal, hard plastic lined spa, only filed a few months ago, cya 30ppm. Water started testing at 2.5ppm CC and FC dissipated rapidly. I was using old chlorine. Added more and more until I finally got FC to shock level. CC tested at 2.5ppm, never changed. At double shock level, still 2.5ppm CC. Aerating makes no difference. Maintaining shock level for days, no difference. Threw out dpd powder (it was crystallized) and bought new. Same thing.

Finally gave up and bought new chlorine, thinking that has to be it. Nope. Shock level, 24hrs, 2.5ppm CC.

Please help. I don't usually feel this dumb.

 

[duraleigh]

Welcome to the forum

How do you know your shock level......can you post valid test results.

 

[st12]

Shock is 12ppm with 30 CYA.

Don't know what you mean by valid test result. Do you mean complete?

FC 12.5
CC 2.5
pH 7.5
TA 120
CH 200
CYA 30
Borates 0
Temp 100

 

[mknauss]

Apparently I can't get into my old account. Anyway...

@Leebo

 

[mgtfp]

This is a spa, right?

Any chance that someone keeps peeing into it? Dog? Angry neighbour?

Are you or were you using non-chlorine shock?

 

[st12]

No chance. Spa is inside garage. I'm the only person in the house. I used granules to get CYA to target, only liquid after. Like I said, was using old bleach at first.

 

[st12]

Set at 12 FC last night & closed cover. Tests this morning show 12 FC & 2.5 CC.

 

[st12]

and it does smell like chloramine constantly, BTW.

 

[Newdude]

only filed a few months ago,

You're supposed to change the water every few months, maybe even less, because of such a small tub. With a 500 gallon tub you'd have 2.5x the gallons to disperse the bather load. You alone in your 200 gallon tub is the equivalent of 170 swimmers in my pool, and said swimmers are cooling down, not heating up and being exfoliated.

The chemistry getting away from you is your sign it's time to dump and start over.

Do you or have you ever purged the tub ? We reccomned ahhsome at water exchanges.

 

[st12]

I have. I've been using tfp for years, both in pool and spa. I've never had anything like this happen. I've never had to do a drain and fill in less than 6 months. I've actually never done one because I had to, just been preventative.

 

[Mdragger88]

I imagine that the old liquid chlorine means that you were behind the 8 ball for a bit with sanitation and unfortunately you can see how hard that is to overcome. The result is persistent cc’s.
Bite the bullet & purge, drain, refill if a few rounds of slam level fc don’t do the trick. It’s only 200 gallons- sometimes things happen. No sense in fighting it. Way less effort to start over.

 

[Bperry]

I have. I've been using tfp for years, both in pool and spa. I've never had anything like this happen. I've never had to do a drain and fill in less than 6 months. I've actually never done one because I had to, just been preventative.

You’re not letting the CC test sample sit around when adding drops are you? The FC/CC test sample can turn back from clear to pink if you let it sit there, which might trick you into adding more drops.

 

[Newdude]

No sense in fighting it. Way less effort to start over.

And money too. You can spend $75 stubbornly battling $0.45 of water.

 

[Mdragger88]

You’re not letting the CC test sample sit around when adding drops are you? The FC/CC test sample can turn back from clear to pink if you let it sit there, which might trick you into adding more drops.

To add to this advice-
also clean your beaker with alcohol as a dirty beaker can cause interference

 

[st12]

Just reporting back. The old chlorine was left over from when I had a pool up, so I had way more than I was going to use with my spa for a long time. No issues with getting behind on chlorine, etc. I did go ahead and drain and refill and adjustments are back to normal. No idea what actually caused it. I was mainly trying to figure out if this was a problem with old chlorine, bad regents, some sort of contamination, or something else I'm just not thinking of. I prefer not to repeat dumb mistakes over and over. Thanks for the help.

 

[Newdude]

Maybe it was a fluke and you or your bathing suits left more residuals this cycle.

 

[Mdragger88]

The only issue that would have come from using old liquid chlorine is that it would be less potent so you wouldn’t get the expected fc rise which might mean fc falling too low. It doesn’t “turn bad” really just turns into salty water with no sanitation power.
So long as you confirmed with testing you were still maintaining adequate fc it wouldn’t be a problem.
To eliminate any doubt about reagents I always try to test with the new ones before I completely run out of the old ones so I can compare.
Glad things r ok now
sometimes you just need to start over which is at least relatively easy in a hot tub.