Drain first or SLAM

[pgjohnson]

So passed an OCLT.

Tested twice last night and same result.(15)
Tested 4 times this morning and got a 0.5 (14.5) drop twice and a 1 (14) drop twice.

Any reason I should continue SLAM for another day as a precaution.

 

[Texas Splash]

Any reason I should continue SLAM for another day as a precaution.

At this point I think you should put the test kit away for a while and relax. You earned it. Go back to normal periodic testing and leave the OCLT alone unless you are confident there's a problem (visible algae, cloudy water, huge FC drop in 24 hrs, etc). Try to get yourself a speed stir at some point and enjoy the remainder of your season.

 

[pgjohnson]

I just want to thank you guys for all the patience and help. I am probably would have quit earlier.

It was really appreciated.

I’m guessing I can now raise my CYA a bit from 30 for a SWG to cope with our extremely hot summers.

Also when you guys get a chance I would like to know the following anyway:

1. From the FAS test page, why would this not be a factor when doing 30 drops and FC around 15? Could be out by 3 drops which is the 1.5ppm I sometimes get

• The precision of the measurement is plus or minus one drop when up to 10 drops of titrant are used, or plus or minus 10% of the final reading, when more than 10 drops of titrant are used.

2. Lets say you think CYA is 30 but its actually 40. Would running a SLAM at 12 instead of 16 work but just take longer?

 

[Texas Splash]

I’m guessing I can now raise my CYA a bit from 30 for a SWG to cope with our extremely hot summers.

Absolutely.

 

[Texas Splash]

From the FAS test page, why would this not be a factor when doing 30 drops and FC around 15? Could be out by 3 drops which is the 1.5ppm I sometimes get

• The precision of the measurement is plus or minus one drop when up to 10 drops of titrant are used, or plus or minus 10% of the final reading, when more than 10 drops of titrant are used.

2. Lets say you think CYA is 30 but its actually 40. Would running a SLAM at 12 instead of 16 work but just take longer?

Normally that isn't a huge issue unless someone's CYA is something like 60 or more requiring 48 or more drops with the 10 ml water sample. But in many of our tests, there is always a smalle of variance assumed with water testing. With consistency and proper testing, an owner can often times eliminate those potential swings.

Lets say you think CYA is 30 but its actually 40. Would running a SLAM at 12 instead of 16 work but just take longer?

It certainly could. At that point, the chlorine-to-CYA ratio is no longer ~ 40%, so it's not as effective.

FAS-DPD Chlorine Test

The FAS-DPD chlorine test is used to find the level of Free Chlorine in the … Read more…

www.troublefreepool.com

 

[pgjohnson]

Thanks so much.

Have not tested my PH yet but normally it is on the high side. At what stage can I start to add acid if I need to drop PH.

 

[Newdude]

Lower the PH anytime you see an 8 or 8.2. Aim for a high 7

Sorry for so many questions

It. Is. Literally. Why. We. Show. Up. Everyday.

Probably many times on said day. Never hesitate.

 

[pgjohnson]

Thank you

 

[Texas Splash]

At what stage can I start to add acid if I need to drop PH.

Let the FC fall down to about 9 before you test the pH.

 

[pgjohnson]

Ok will do.

 

[pgjohnson]

So as mentioned at the start of the thread I did an AA treatment back in June for iron stains which was successful. Now that the SLAM is completed I can see very light staining around large parts of the pool which I'm sure will be the iron which has come out of suspension after I added the sequestrant in June.

Was trying to find where I saw on TFP that you could add a sequestrant without doing AA treatment and it could possibly lift new stains. Was wondering if I should attempt this?

 

[pgjohnson]

So in the page for ascorbic acid treatment it says the following:

• As you slowly raise the chlorine, watch for stains starting to form.
• If you see stains, make sure the ph is no higher than 7.2, and add more sequestering agent. You should see the stain lift in a couple of hours.

Is this only directly after an AA treatment or could it work just as stains are reappearing from my SLAM.

Or should I now add a sequestrant anyway that the stains are reappearing?

 

[Texas Splash]

Is this only directly after an AA treatment

Yes because the AA and chlorine don't work together. That's why the FC must be close to zero before the AA. There may some brands of iron/stain products designed to work with some chlorine, but I don't recall off the top of my head.

This time of your for you, I would just control what you have for now. Consider another AA either at the very end of the season or very early next year while the water is cold.

 

[pgjohnson]

So should I still add some sequestrant anyway to stop further staining?

 

[Texas Splash]

So should I still add some sequestrant anyway to stop further staining?

You sure can, but I would wait until the FC comes down to normal levels. With an elevated FC level, it will just tear-up the sequestrant.