questions about SLAM process

[archer636]

1 - the procedure says adjust pH beforehand. I know for a fact that adding chlorine raises pH. Also, chlorine is ineffective if pH rises above 8. How do you maintain effectivity during the process without adjusting pH?

2 - I need to maintain shock level (FC=24 for CYA=60) until OCL is less than 1 ppm. At that point, how do I get back to normal levels? It will at least 18 days (not considering the sun) to get back to FC=6.

 

[AimeeH]

Why do you say chlorine is ineffective above 8 PH?

If you lower your PH to 7.2 you should stay in reasonable range for SLAM. The PH test becomes ineffective when chlorine is above 10 tending to give false high readings.

You're done with SLAM when:

Water is clear
CC is less than .5
OCLT is 1 or less.

Let chlorine drop on its own. Test and add more when within range between minimum and target.

 

[Piolin]

1- the test for pH is the one ineffective, FC will work just fine...

2- FC will drift back by itself much faster than that...

8,400 gal 3K GPH pump, SWG CG-28669, TF100 test kit, speed stir, K-1766 Taylor salt test.

The corner stone of TFP
Pool School - Chlorine / CYA Chart

 

[jblizzle]

Yes adding bleach will raise the pH some which is why we say to lower it first. When the FC is consumed, the pH will drop back down, bleach is effectively pH neutral.

It is NOT true that the chlorine is ineffective at high pH. With CYA in the water, the chlorine remains effective.

The OCLT looks at the loss at night with no sun on the pool. The sun will burn off the FC very quickly, likely down to normal in a couple days. But, it is safe to swim at shock level, so there really is no need to wait.

 

[duraleigh]

1. You adjust pH down to around 7.2. Then you add the chlorine. The immediate effect of adding chlorine does create a small rise (well within the 7's) and once the chlorine converts to it's effective form in your pool HOCl, the effect is ph neutral.

2. Almost all pools lose at least 2-3 ppm daily....some a bit more. At SLAM values, that loss is quite a bit faster. You should be back to maintenance levels in just a few days. You can swim anytime after you stop the SLAM.