Update on excessive bleach consumption

[VOLDADDY]

I have still been losing FC overnight, for over a week now, and I have been hammering away with bleach2-3x a day. I tested last night and my FC was at 6. I decided not to add any bleach and see where I would be this morning. I turned my pump off and added the Aquabot to the pool. This morning I ran a full test on all of my numbers and here is what I have:

FC 6!!
CC 0
TC 6
PH 7.5
Alk 120
CYA 25

2 quick questions-my FC didn't drop 1 bit overnight and I didn't add any bleach, yet when I was hammering away with bleach, I was losing FC every night. Could it just be a coincedence that the alien life form that invaded my pool finally died/left last night? Maybe they needed high FC levels to sustain their life forms...LOL.

2nd, my CYA dropped from 40 to around 25 in less than 2 weeks. I will add to bring back to about 40. Would a constant barrage of bleach 2-3x daily dilute the CYA?

Thanks.

[duraleigh]

VOL,

Could it just be a coincedence that the alien life form that invaded my pool finally died/left last night?

Yes. Once you clear the pool of organics, your nightime consumption will stop. That happens at some point and apparently your point was last night

2nd, my CYA dropped from 40 to around 25 in less than 2 weeks. I will add to bring back to about 40. Would a constant barrage of bleach 2-3x daily dilute the CYA?

No, the bleach won't do it. I would suspect the vagaries of the testing method. You might try another test before you decide to increase it too much.

[mwsmith2]

2nd, my CYA dropped from 40 to around 25 in less than 2 weeks. I will add to bring back to about 40. Would a constant barrage of bleach 2-3x daily dilute the CYA?

Thanks.

No, the bleach would not have any impact on the CYA levels, BUT you are showing symptoms of what I've suspected: something is biodegrading your CYA. I was kinda wondering if your CYA levels had dropped mysteriously recently. If I remember correctly, you did add some CYA, and that may have covered the fact that some of it had been degraded.

This biodegradation is primarily anaerobic, and produces ammonia as a result of the breakdown. This creates a prodigious Cl demand, much like what you have experienced.

The one thing that puzzles me is that your CYA seems to have dropped while you were beating away at it with large doses of Cl. I'd think that whatever it was would have been nuked by those high Cl levels. This is why that kind of CYA degradation usually happens over the winter in uncirculated, low Cl pools. It's highly unusual for this to happen in a operating pool, unless you have some secret dead spot somewhere....

Michael

[VOLDADDY]

I did add CYA about 2 weeks ago, and my CYA level was 40. It is now down to around 25. I will add more in a stocking to get back up to around 40. What causes CYA degradation and what can I do to stop it? Thanks for all of the help Michael and Dave!

[duraleigh]

VOL,

I don't know of a cause to lose CYA in an opened, swimmable pool.
(Winter...yes)

I would chalk it up to "one of those things" and go back to 40ppm. I'll bet you stay there all Summer.

Say, were you chit-chatting on that new, waterproof phone and having an adult beverage when you did that 25ppm test? Yep....that explains it!

[CarlD]

I cannot remember if CYA degradation is caused by ammonia or causes ammonia levels to rise. I do know that they are connected, but I don't recall which way.

[mwsmith2]

I cannot remember if CYA degradation is caused by ammonia or causes ammonia levels to rise. I do know that they are connected, but I don't recall which way.

The byproduct of CYA degradation is ammonia. Of course, normally you get CC out of that, but not here. This is definitely a very strange case.

Michael

[VOLDADDY]

VOL,

I don't know of a cause to lose CYA in an opened, swimmable pool.
(Winter...yes)

I would chalk it up to "one of those things" and go back to 40ppm. I'll bet you stay there all Summer.

Say, were you chit-chatting on that new, waterproof phone and having an adult beverage when you did that 25ppm test? Yep....that explains it!

LOL..well, now that you mention it, I did see 3 tubes.

BTW, I highly recommend that Uniden phone from the "L" store. It is awesome! It is totally waterproof, and we made sure of it. My 2 year old dropped it in the pool. It floats to the surface, and works like a charm. Well worth $60 IMO. That's 2 jugs of Baquacil for me Of course, I am on the BBB plan now, so I can buy new toys for the pool, and still save $$$.