General Question about SLAMMING

[Catanzaro]

Luckily in my first year I have not had to go through the SLAM process. Pool is closed. I enjoy the forum and most questions and the learning process is answered by reading posts occasionally. But I do know that next year I will have to help friends with this problem.

So my question is as follows:

Why does the PH about to be adjusted between 7.2 and 7.5 while SLAMing? I fully understand the reliability tests at higher chlorine levels, etc. I doubt most people would go swimming if they had a green pool unless it was cleared up. Once cleared then the PH can be adjusted accordingly. Does the PH rise while SLAMing? Can the PH just be left alone if it was between 7.4 and 7.8, or could some damage be caused to a Vinyl Liner or plumbing during the process?

 

[tim5055]

You can assume that during the SLAM pH is going to rise some. Heck, just the added areation of brushing and running the pump 24/7 is going to cause rise.

Bringing it down to 7.2 before you start gives you head room for rise during the SLAM.

 

[Catanzaro]

I guess maybe I am asking if the PH has to be adjusted or this can be done after the SLAM process? Then again, the TA will drop and you will be in the same position to increase TA, etc. Best thing to do is never get to a SLAM unless it just happens.

 

[duraleigh]

I guess maybe I am asking if the PH has to be adjusted or this can be done after the SLAM process?

I'm not sure I understand. Is there a specific reason you do NOT want to adjust pH beforehand or are you just curious as to why?

The "why" is simply because you are working towards having your pool water within suggested guidelines and pH is the first parameter to adjust. I can't think of a a scenario in which you would not want pH within guidelines first.

 

[Catanzaro]

Curious to know why? That is all.

As I mentioned before my pool is closed and I have had great success with the TF-100 kit and luckily I found this forum in my first season before I ran into problems. And believe me if I listened to the Pool Store my CYA level next year would have been 100 + and probably full of metals.

Wanted to know if I help a friend clear up a pool next year if the PH can be lowered (assuming it is high) at the end of the SLAM process. But I will follow the instructions accordingly if I have to help a friend.

 

[Smykowski]

You can assume that during the SLAM pH is going to rise some. Heck, just the added areation of brushing and running the pump 24/7 is going to cause rise.

Bringing it down to 7.2 before you start gives you head room for rise during the SLAM.

I think this pretty much explains it. It's exactly how I would have replied if I saw the question first.

 

[Catanzaro]

Thank you everyone

 

[singingpond]

Take a look at this thread, if you haven't come across it before:
http://www.troublefreepool.com/threads/24440-Lowering-PH-before-shocking

Thread was started in 2010, but there are some updated posts from 2014 also; interesting comments from chem geek and other knowledgeable posters.

 

[Swampwoman]

^in other words, lowering ph to 7.2 makes the slam work better because chlorine is more effective at lower ph

 

[chem geek]

Well, the reason I gave for lowering the pH first wasn't so much for chlorine effectiveness though that is a factor, but rather that the pH when adding a lot of chlorine goes up a lot and can risk metal staining or cloud the water with calcium carbonate which then has one think the pool isn't getting cleared of algae when it really just needs the pH lowered (say, by letting the chlorine level drop back down).