Do I need to find chlorine breakpoint?

[kcindc]

OK. So 2 questions:

1)CC is already at 0.5. Do I even need to SLAM? (water is clear NOT Crystal; minor algae dust during brush)

2) IF YES, then I add 581 oz to achieve a Shock FC of 20 ppm, I am done if 1) water crystal and CC is 0.5 or less; AND 2) OCLT is less than 1ppm. so if I SLAM tonight to achieve 20 ppm; a 19ppm the next morning would be an acceptable OCLT. Correct?

I am not sure if I am reading the SLAM directions correctly or not. Thanks.

You can't stop the SLAM until your pool is crystal clear. You must pass all 3 criteria before you finish and none of the criteria is an "OR".

Once your water is crystal clear, you can do the OCLT.

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Oh, not sure if the was already mentioned, but some algaecides add metals, so you need to stay away from them.

It is best to stick with polyquat 60% and verify that it doesn't contain copper or other metals. Around here, we recommend only using algaecide under a few situations like closing your pool and when you purposefully need to bring your FC to 0, like during an ascorbic acid treatment.

 

[Poolboy6]

Right. So if starting the SLAM tonight and I achieve Shock FC of 20 and maintain. I am looking for a morning with an FC of 19 and CC of .5 or less. Is that not correct?

 

[jblizzle]

Is the pool also crystal clear and sparkling? If not, you are not ready for the OCLT.
But, yes if your last test was 20ppm, you would want it to be no lower than 19ppm in the morning.

 

[Poolboy6]

Great. Thanks. I appreciate the hand holding.

 

[R.J.]

...AND the water is crystal clear. Test the FC at least 30 minutes after your last dosage of bleach (and after the sun is no longer shining on the pool), then test in the morning before the sun hits the water. Even if you pass the OCLT you might not be finished because it sounds like you still have dead algae to be filtered out. Be patient and don't skip a step in the SLAM process. If you don't pass tomorrow morning you will need to be diligent about maintaining shock level, testing and dosing as often as necessary to stay at shock level.

 

[Poolboy6]

Update: from the above numbers I began to SLAM.
3:30
FC: 27.5
CC: 0.5
5:30
FC:18.5
CC: 0.5
7:00
FC: 22.5
CC: 0.0
I am now stopping. And will check in early morning OCLT. Does this look right?

 

[jblizzle]

Looks fine. A bit of an over-shoot there, assuming the target was 20ppm

 

[Poolboy6]

Indeed. I made an error on the dosing calculator.
Thanks!! Will let you know his it goes.

 

[Poolboy6]

Update:
Saturday evening
FC: 21.0
CC: 0.0
Sunday morning
FC: 20.5
CC: 0.0
Passed the OCLT. WOW water is the clearest I've seen it in the 8 years owning the pool.
THANKS Guys. Grateful for the schooling and help!!
I will let now let the FC drop naturally and keep between 4-6 ppm...and check CYA often.
Needless to say, I will not use dichlor or the pool store ever again!! Any thoughts on the use of trichlor pucks as my stabilizer? as I now know this is contributing to the CYA problem? What about eliminating completely and just using liquid? thoughts on moving forward?
Thanks again!!

 

[kcindc]

Glad you passed the OCLT.

Using pucks will increase your CYA, so save the pucks for when you go on vacation or when you need to increase your CYA. Otherwise, we suggest that you use bleach on a daily basis. Keep a log and you will see your pool's pattern. Test FC, CC and PH daily. TA and CH weekly (if you have very high or very low CH fill water). Test CYA after water replacement or once a month or so.

 

[Poolboy6]

So I passed OCLT 3 days ago and the Water is crystal clear. However, upon brushing this morning I noticed light algae dust--what gives?

FC: 15
CC: 0.0
PH: 7.5
TA: 90
CH: 300
CYA: 50

 

[jblizzle]

You sure it was not just dust/dirt?

 

[kcindc]

Were you brushing and vacuuming daily before you did your OCLT?

 

[Poolboy6]

Yes brushing and vacuuming daily before, during and after SLAM and OCLT. I suppose it could be dirt but it is on every surface. Thoughts?