Done with SLAM now need some help with maintenance....

[Kimnlogan]

We got the pool done with the SLAM process last week but not exactly sure what we need to do for maintaining levels. So far, CYA and alkalinity and pH seem pretty stable but chlorine is still needing daily additions of bleach.

Last evening my FC was 2 and CC was 0. Added recommended amount of bleach per pool math. We then got about 2"of rain to complicate things...

Today's numbers

FC 5.5 (not up to our goal of 6 but assuming that is due to the rain?)
CC 0.5
TA 100
CYA 45
pH 7.5 + (I'm not the greatest at estimating the color but it's at least 7.5)


How often should I expect to have to add bleach? Our pool gets sun from morning until about 4pm when it is then shaded the rest of the day. We seem to be dropping to that low level of 1.5-2 every evening.

 

[Richard320]

Bleach is a daily thing. What is your current CYA? Now that the SLAM is done, you should get it to 40-50 range. Then keep a close eye on consumption. You want to target the FC so that it doesn't dip below the minimum for your CYA before you add the next time. In a week or so, you'll have a pretty good idea what the pool's appetite is.

 

[Kimnlogan]

Ooops... CYA is 45. Added to original post.

 

[Richard320]

Ooops... CYA is 45. Added to original post.

That makes it easy, then. Your minimum is 4 FC. Target 7. If you find 4.5 the next day, perfect! If you find 5, target 6.5 the next time. Just whatever it takes to stay above 4.

 

[Kimnlogan]

Ok...great, thanks! Should I expect to have to add daily?

 

[Richard320]

Ok...great, thanks! Should I expect to have to add daily?

A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

 

[pooldv]

I tend to be a little looser with adding bleach when I am not around or not swimming. The rules I follow with chlorine in my pool is to never let the chlorine level drop below the minimum level for the CYA level. But, it is fine to go up to the shock level to make sure that chlorine stays above minimum if you can't add for a couple of days. You will get a pretty good feel for your usual chlorine consumption after a period of time and taking some notes to see patterns.

It is also noteworthy that it is safe to swim when the chlorine level is above the minimum and below shock level for your CYA level. Here is the all important Pool School - Chlorine / CYA Chart

 

[Kimnlogan]

Thanks all... going to take a while to get used to. Don 't mind tending to it daily.. just wasn't sure if I should expect to actually need to ADD bleach daily. I guess this is why the chlorine feeders became popular at some point... plop the tabs in and let them sit.

 

[Kimnlogan]

Ok... so here is where we are... we keep having chlorine drop quite a bit so I added what I had last night (not enough for shock level but to boost it up)

Last evening...
FC 12.5
CC 0

This morning....
FC 12.5
CC 0

This evening...

FC 4
CC 0.5
TA 80 (this has dropped from 100 three days ago)
pH 7.5 (nice and stable)
CYA 35 (this has dropped from 45 three days ago)

????Thoughts... (I guess with the new CYA of 35 the FC of 4 is fine since it's the low limit but why such a huge drop in 12 hours??)

 

[Kimnlogan]

Ok... so here is where we are... we keep having chlorine drop quite a bit so I added what I had last night (not enough for shock level but to boost it up)

Last evening...
FC 12.5
CC 0

This morning....
FC 12.5
CC 0

This evening...

FC 4
CC 0.5
TA 80 (this has dropped from 100 three days ago)
pH 7.5 (nice and stable)
CYA 35 (this has dropped from 45 three days ago)

????Thoughts... (I guess with the new CYA of 35 the FC of 4 is fine since it's the low limit but why such a huge drop in 12 hours??)

Anyone???

 

[Richard320]

Ok... so here is where we are... we keep having chlorine drop quite a bit so I added what I had last night (not enough for shock level but to boost it up)

Last evening...
FC 12.5
CC 0

This morning....
FC 12.5
CC 0

This evening...

FC 4
CC 0.5
TA 80 (this has dropped from 100 three days ago)
pH 7.5 (nice and stable)
CYA 35 (this has dropped from 45 three days ago)

????Thoughts... (I guess with the new CYA of 35 the FC of 4 is fine since it's the low limit but why such a huge drop in 12 hours??)

You lose percentages of FC to sunlight, not a fixed amount per hour. Higher FC levels means it disappears faster, which is why you can't just dump in a week's worth of bleach once a week. Lower CYA levels means it gets attacked by sunlight worse.

Here''s a graph stolen from Pool Water Chemistry

https://www.troublefreepool.com/~richardfalk/pool/ChlorineLoss.gif

At 35 CYA and 10 FC you can expect to see a loss of about .8 FC/ hr. So if it was 10 hours between tests, it's nothing to be alarmed by.

 

[ship of fools]

Anyone???

That is an awfully big drop for one day.

Is the pool clear and sparkling?? With a big drop like that and a CC reading of .5 you may have algae still.

The CYA won't drop that much but variations in your reading are normal. I would go with a number of 40 if i had readings of 45 and 35. Make sure you never go below the minimum for 40.

 

[Kimnlogan]

So I can assume since I had no chlorine loss overnight that it's mostly sun and bather load then, correct?

Oh and ETA: this morning FC was 4 again with a CC of 0.

 

[Azgirl71]

So I can assume since I had no chlorine loss overnight that it's mostly sun and bather load then, correct?

Oh and ETA: this morning FC was 4 again with a CC of 0.

Yes that is what you can assume. Just add bleach as needed to keep FC at target level or even 1-2 ppm above target level. I keep mine 2 ppm above my target level, so I don't have to worry if my SWG stops working.