First SLAM

[MorganJ]

Hi all, i did my first OCLT last night, and went from 8ppm to 4ppm. based on that result i want to do my first SLAM. i’ve watched the video on the site, but wanted to confirm a few things.

Is step one to bring my CYA up so the pool can handle the increase in FC?

here are my latest readings as of today:

FC: 2.0

PH: 7.4

TA: 100

CYA: 25

 

[Bperry]

Hi all, i did my first OCLT last night, and went from 8ppm to 4ppm. based on that result i want to do my first SLAM. i’ve watched the video on the site, but wanted to confirm a few things.

Is step one to bring my CYA up so the pool can handle the increase in FC?

here are my latest readings as of today:

FC: 2.0

PH: 7.4

TA: 100

CYA: 25

If those numbers came from a TF-100 or K2006C then your CYA is fine. The CYA test is way easier when you just fill the sample up to each line in the tube and check if the dot is visible or not. Doing it that way will make your CYA value be either 20 or 30. Since we always round CYA values up to the nearest decade, your CYA is 30ppm. So if you’re sure the CYA is at least 20ppm, then your SLAM chlorine level is 12.

But the sun out here has been making it crazy hot which seems to burn off both CYA and FC so make sure your CYA is 30. You don’t want to increase your CYA right before a SLAM unless it’s less than 30ppm.

 

[MorganJ]

i have a taylor test kit (k-2006 salt)

the CYA test is interesting. the lowest reading it offers is 30, and i can still very faintly see the dot when it’s completely filled up. that’s what i’m guessing it’s between 20-30, but it sounds like i can round that up.

another potentially silly question, is a pool safe to swim in during a SLAM?

 

[HermanTX]

another potentially silly question, is a pool safe to swim in during a SLAM?

There are no silly questions. You can swim up to SLAM level - in this case 12ppm with CYA of 30.
However, you should be able to see the bottom of the pool. It is a safety issue - that you can see someone at bottom of pool.

Ensure to test your pH again and adjust to 7.2 to 7.4 range.

The main important point is that a SLAM process goes better if you can MAINTAIN the FC at SLAM level. So test every 3-4 hrs during the day and bring it back up to SLAM.

 

[MorganJ]

May I ask why you need to adjust PH to the 7.2-7.4 range? I've seen that outlined but I don't understand why

 

[Bperry]

May I ask why you need to adjust PH to the 7.2-7.4 range? I've seen that outlined but I don't understand why

Because the pH will rise over the course of a week or two and the chlorine will be high enough that the pH test becomes invalid. So it’s a way to ensure the pH stays in the 7’s until you’re done.