CYA/shock question

[erivette]

My pool is sparkling clear but I had CC of .5. I never have CC's so I did the OCLT and failed. I began the shock process yesterday morning. My CYA was about 25 so I was shocking at 12. But here in HOT Texas I needed to get my CYA up so I put in enough stabilizer to get me to about 40 CYA. I've never added CYA while shocking. In fact, I haven't had to due the shock process in about 4 years thanks to BBB and my TF100 but I was lax in my testing for a week(ish) My fault! Anyway, I know the CYA won't show up for about a week. So do I stick with shocking at 12 or do I go ahead and up it to 16 now? Latest numbers:

FC 12
CC .5
PH 7.5 (before shock process began)
TA 190
CH 220
CYA 25 (will be 40 in about a week)

Thank you!!!

 

[woodyp]

Take your shock value up to the level you added CYA for. I keep mine at 50 here in East Texas and still lose almost 4 ppm daily in full sun. I feel for ya'!

 

[duraleigh]

Shock up to 16. Once you put CYA, assume it is there even though it doesn't show on the test.

 

[erivette]

Just increased to 16. I have vacuumed and brushed the entire pool several times. I don't see anything. It's sparkly beautiful. I'm at a loss as to what's in there. :?: But I keep getting CC .5. No light niches and checked ladder. Oh well I'll keep it at 16 until I pass OCLT.

Woodyp - I don't dare use the solar cover to decrease FC loss or evaporation because the pool would get over 100 degrees.

Please send all that rain out east Texas' way.

Thanks again!

 

[duraleigh]

But I keep getting CC .5

back up to Pool School for you CC's of .5 ppm are treated the same as zero for our purposes.

1. Your pool water is sparkling
2. Your CC's are .5ppm or less
3. You can hold your FC overnight without losing more than 1ppm.

Looks like all you have to do is get #3 accomplished and you are good to go.

 

[erivette]

My pool is sparkling. I've had 0 CC since late Saturday but cannot maintain FC overnight. I lost 3 FC from 9pm to 7am. I have not let FC drop below 16. I've vacuumed and brushed everything many times. Latest readings:

FC 17.5
CC 0
TC 17.5
PH 7.5 (before I started shocking)
TA 190
CH 220
CYA 25 (added 2-1/2 lbs stabilizer last Friday so will be 40 soon)

What could I be missing or doing wrong? Is there anything else I can try? I'm almost out of R-0871 and hope it lasts till I get more. I've gone thru 14 gals of 10% bleach and 3 gals of 8.25% bleach since Thursday. Thank you!

 

[RobbieH]

You've only been going a couple of days? It can take weeks, time to open some POP! (Pool Owner Patience!)

 

[erivette]

I know it can take weeks when you start with a swamp or lots of algae/organics. Mine has been sparkling all along. No visible signs of anything in pool, it's not slimy feeling, nothing. I only began shocking because of .5 CC and attempting OCLT and failing. I've had the misfortune of the swamp experience years ago and had POP for that mess. But I guess it's a little harder when you see/feel nothing causing the issue and are at a loss for what's going on in the pool to burn up all that FC along with 0 CC for about 2 days. I guess I was hoping one of the pool gods on here would notice a step I've overlooked or could tell me something else to attempt. I will continue on until passing OCLT. But if someone has any ideas please let me know. Thank you.

 

[JasonLion]

What you describe does happen now and then, though it is rather rare. Make sure the failure to pass the OCLT is not testing error, or sunlight related.

 

[RobbieH]

The pool I've been talking about today, taking 4 weeks, always looked almost perfect. It just had an odd FC usage and a little green on the steps. Start with Jason's recommendation and we will go from there.

 

[erivette]

Thank you both! I'll keep at it until I have good news with OCLT. I go back to work tomorrow so I will overshoot 16 in the morning and hope it lasts until I get home. I just remembered, I had put enough liquid stabilizer to get me to 40 CYA when I had my liner replaced first week of June (was testing 40-45). Somehow by last weekend in June I was down to 25 CYA (tested several times to confirm and have never had trouble with performing this test). No rain to speak of and very few in pool. Not that it's related but that's the only other odd thing that's happened.

 

[RobbieH]

My CYA varies around 10 ppm from test to test. I just chalk it up to testing error. Could be the brightness of the sun or my ability to see that day.