I am a newbie, check my math please

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I ran home at lunch and re-tested. Pool is in full sun from around 7:45am to 3:00pm.

FC 15 (that is where it was this morning, I posted 13 by mistake. 15 is my shock level.)
CC 0
PH 8.0

I will go ahead and re-do the OCLT as advised. I probably won't have to add much chlorine, if at all, to get back to shock level before tonight anyway.

So should I add the salt, wait for the FC level to fall below 10ppm and then adjust the TA and PH and then add the borates? Plug the SWG back in at 5ppm and adjust it stay between 3-5ppm. Shoudn't I raise the CYA back up also. Per pool school 70-80ppm for plaster w/SWG. When should I adjust that?

Thanks for all the help. This has been fun. Sounds crazy but, my pool is looking great and I have only spent $11.00 on chlorine plus the test kit. It is so good doing your own test and knowing the real numbers.
 
Sounds like a plan. :goodjob:

Remember that adjusting the TA is a process (see Pool School) and could take some time to get it in range before you can add the borates.
You can add the salt at any time and start dialing in the SWG even before you get the TA set.

Bumping the CYA up is also a good idea, you can start that as soon as the shock process is done ... remember it takes a week to show up on the test.

You should probably try to set the SWG to hold the FC closer to the target level than the minimum so you have a small buffer.
 
I'm confused again. I continued to test FC yesterday. It fell to 13 so I adjusted it to 16.6 (the amount of bleach I had left)around noon. At 10:30pm it remained at 16.5. I had added 4 bags of solar salt around 3pm. I tested FC this morning at 7am before sun hit the pool and it dropped to 10.5. The CC has always been 0, no pink at all. The water looks immaculate. No signs of any algae. I cleaned the filters yesterday before adding the salt preparing to add CYA, since I won't be able clean for a week. The pressure hadn't incraesed more than a couple PSI. The filters looked clean but I could see a little green tint in the water coming off the filter. Am I done shocking or do I need to keep it up? I don't understand why my FC holds pretty well throughout the day and then falls overnight. I know that means contaminants but, why doesn't it drop in the daytime and why no CC if I have algae still? I don't what to do. I don't want to quit early and have algae return. We are supposed to host a swim party this Friday. Will it be ok to swim by then, even if my FC is 10?
 
that does sound a little odd. I would maintain the pool at shock level and try the OCLT again tonight. The water is safe to swim if the FC is less than the shock value, plus some other criteria that you already meet.

Posted from my Droid with Tapatalk ... sorry if my response is short ;)
 
Is it possible you are not using enough of the powder? High FC takes more than low FC - maybe your scoop at night was larger than the one you used the next morning? My scoop eventually started filling up with crusted powder despite keeping it dry. Eventually I had to rinse it off and let it dry to keep from having to use two scoops to test at higher FC levels.
 
I would not stop the shocking process yet...but was there sun on the pool between the 10.5 measurement and the 10 ppm you just got? Even if there was, I would suspect you are still loosing more than 1 ppm FC overnight.
 
larryca said:
I'm confused again. I continued to test FC yesterday. It fell to 13 so I adjusted it to 16.6 (the amount of bleach I had left)around noon. At 10:30pm it remained at 16.5. I had added 4 bags of solar salt around 3pm. I tested FC this morning at 7am before sun hit the pool and it dropped to 10.5.
Click to expand...

Theoretically you need to do an OCLT this way:
Wait for sun to be off the pool, Measure FC, add bleach to reach desired level, wait an hour, measure FC, wait overnight, measure FC - is that what you did? If so how did you get the 16.6 FC value? How much bleach did it take to get from 13 to 16.6?
 

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The sun was coming up but not hitting the pool yet. Yesterday, I used calculator to see what effect adding the remaining amount of bleach I had left was. It was 16.6. I added it and then tested later that night and still had 16.5. Never actually tested to see the 16.6. Jut assumed the calculator was correct. Could have went higher and then fell back to 16.5 I guess. But my daytime losses have been low. The 13 to 16.6 was supposed to be 64oz. I had half a gallon left and that's what I added. I am using 10% chlorine liquid. It worked out to be cheaper than 6% bleach because Orchard Supply has a two gallon box on sale for $5.86.

Update 10:30am -I just re-tested FC and got 9.5 and CC of 0. There is sun on pool now. I added an entire gallon of !0% chlorine and will re-test in an hour to confirm 16.5.
 
I did test in the evening, I just didn't test earlier that day after adding the chlorine to raise the level back up. I can only assume what the peak was earlier that day based on what the calculator said it would do.

Today, one hour after adding the gal of 10% chlrorine the FC is at 19.5 and CC is at 0. Per the pool calculator, the one gallon should have got me to 16.5. I probably had the same thing happen yesterday. Level was actually higher than assumed and I did suffer some loss during the day. I will test again after dark tonight and re-test early in the am and see if I pass.
 
Overshooting would be due to either the pool having less water than you think, or the liquid chlorine being stronger than you think, or both.

If you are continually overshooting with different bottles of chlorine, purchased at separate times from different places ... then that would point more toward a water volume issue.

Likely it is a little of both.
 
Well, the blueprints for the pool say 13,900 gal. The builder says they doug it a little deeper. I know I had them stretch one end out a little wider than planned and it is about 6" deeper in the bottom then planned. I always figured about 15,000 gal. I don't know for sure. The salt I added before I started all this and the PH adjustments I have made before based on the pool calculator have always been spot on. Today is the first time I have verified a difference and it was a brand new box of chlorine I bought seperate from the prior ones. Several times throughout the shocking process I have had to adjust from 13 or 13.5 to 15 and it worked out perfectly. So I don't know. Maybe I bought some hot chlorine? But at least I know for sure where it peaked today. I will test it as soon as I get home form work and then again after dark.
 
Reread the thread. Is the SWG turned off? If not that is why you might overshoot. Also you need the swg off when doing the OCLT. If it is and I missed that detail forgive me I'm on my phone.
 
It has been unplugged since I started the shock process. Someone told me to do that way back in the beginning.

I checked my FC level at 6:00pm and it fell to 10.5. So it dropped 9ppm in 6 1/2 hours of full sunlight. Given that my CYA is still only 40, does that sound right?
 
larryca said:
It has been unplugged since I started the shock process. Someone told me to do that way back in the beginning.

I checked my FC level at 6:00pm and it fell to 10.5. So it dropped 9ppm in 6 1/2 hours of full sunlight. Given that my CYA is still only 40, does that sound right?
Click to expand...

It does to me. My shocking burned through at least 7ppm during the day for a few days. I have partial shade.
 

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