clarrification on TFP shock procedure

[Rossko]

I got my TFT-100 and already love the precision of the FAS test.

I used the calculator and put in my bleach to shock and hit my target right on when checked in 2 hours. Plan to check water in AM before sun gets to pool.

I was reviewing the overnight test and shock procedures and have a 2 questions:

1. Does it matter what the FC level is for the OCLT? Can I measure it at shock level or should I let the sun burn it down to 5 or so to do the test? I doubt I will be able to keep the shock level through the day tomorrow (forecast over 100 degrees sunny) and I'll be at work.

2. My CC is reading 0.5 (just 1 drop re-cleared) - did I read the shock procedure correctly that if I drop no more than 1 ppm FC and my CC is STILL 0.5 then I'm "done with shocking"? I thought I wanted 0 CC - in fact that's why I went ahead and shocked without doing an OCLT first. My water is very clear but I have recently had a few little green algae spots on the steps; so I assumed it needed shocking.

In other words, is it ok to have a pool with CC (0.5 or less) if the overnight drop in FC is less than 1 ppm? And is the OCLT just as valid at a starting value of 16 as it would be at a level of 5?

Thanks in advance.

 

[jblizzle]

1. I prefer the OCLT to be done at an elevated FC or shock valve. So no reason to wait for it to drop.

2. It is completely normal to have some CC show up sometimes. If you only see 0.5ppm, then it is nothing to worry about.

Sounds like this may be a VERY short shock process.

 

[jcowart]

You can do the over night test at any FC. Just looking for less than 1ppm drop. Look at .5 as zero. and water clear.

EDIT: Dang your fast.

 

[jblizzle]

EDIT: Dang your fast.

what do you mean ... you had 9 minutes to beat me on this one

 

[Rossko]

ok, thanks guys

 

[Rossko]

A follow up question:

OK so my FC stayed at shock value (16 for cya of 40) and CC stayed at 0.5 and my water is clear so I think I'm done shocking.

My question is that I got a late start last night any raised the FC up at about 9 PM, confirmed shock level at 11 PM, and then my AM test for the OCLT was at 6:40 AM - so the "OVERNIGHT" delta time was 11 PM to 0640 or 7 hours, 40 mins - was this long enough to see the 1 ppm drop if I were going to?

Thanks (again)

 

[Butterfly]

Yes. You are done shocking

 

[Charlie_R]

I am just curious, did you actually have an algae problem? Or were you shocking your pool just because that seems to be the routine suggested by almost every pool store?

If it was a "routine shock", I think you will find that if you keep good control over your pool chemistry, you will almost never have to "shock" your pool.

Now that you have a great test kit, you will be able to watch your balance a whole lot better than if you were relying on PS testing.

 

[Rossko]

Charlie_r:

I have another thead on my saga. Was posting here because it was shock question. I had begun to see little round spots of slimey green algae. My SWG was broken. I was pool stored and wound up with way high cya. I did a partial drain refill and it rained 8 inches that day and only then did my water turn cloudy. I fohnd this place and decided to use bleach until I fix the SWG. So I had to order tft-100. I used left over lithium hypochlorate to shock in meantime and that did clear water but cojld not measure fc over 5 so not sure if it completely worked so thats why I shocked once I got the tft 100 and did oclt per pool scool

 

[Charlie_R]

Thanks for the brief summary. That will teach me to check for other threads first.