Questions about my SLAM

[Mypool12]

I just opened my pool and I started my SLAM this morning. My readings were as follows:
CYA 30
FC 0
pH 7.5
ALK 65

At 9:30am the pool Math told me to put in 3 gallons and 1 quart of 10% chlorine for shock level of 14 (app called for 12 but I thought I would go a little bit higher). At 1:00 my pool had no FC in it. I just now added 3 gallons at 12% chlorine and got a reading of 15 FC.

How often should I be testing the chlorine to make sure it doesn't go to zero again? I was shocked at how quickly it went to zero or near zero.

Thank you in advance for your help.

 

[thetekgeek]

At the beginning of the SLAM, it's not uncommon to test/dose every few hours, if you have the time available. Once the FC loss starts to slow down, you can extend the time between tests and bleach additions.

Try not to overshoot. You waste the excess to the sun and also run the risk of bleaching your liner.

Did you drop your PH to 7.2 before beginning?

 

[Mypool12]

At the beginning of the SLAM, it's not uncommon to test/dose every few hours, if you have the time available. Once the FC loss starts to slow down, you can extend the time between tests and bleach additions.

Try not to overshoot. You waste the excess to the sun and also run the risk of bleaching your liner.

Did you drop your PH to 7.2 before beginning?

Thank you for your reply. My notes from the TFP website said to maintain a pH of 7.2-7.5. I was at the upper range and did not reduce it to 7.2. I hope this is OK.

 

[thetekgeek]

The reason for dropping the PH down to 7.2 before beginning the SLAM is because the PH test is invalid at FC levels above 10. It is your call, but if it were me I would probably test the PH one more time if you have a FC test that is below 10, make the PH adjustment and then bring the FC back up to SLAM level. You can safely add bleach about 30 minutes after you add the muriatic acid so it shouldn't cost you much time during your SLAM. Here is the link to the SLAM process in case you need it. SLAM - Shock Level and Maintain - Trouble Free Pool

 

[Richard320]

If your pool is green and sludgy looking, you might need to test and add bleach every hour at first. Then as the color changes, it will retain more and more so you can stretch the intervals out. A real foul-looking pool could eat the chlorine almost as fast as you pour it in. Which is a longwinded way of saying it sounds normal.

 

[Mypool12]

The reason for dropping the PH down to 7.2 before beginning the SLAM is because the PH test is invalid at FC levels above 10. It is your call, but if it were me I would probably test the PH one more time if you have a FC test that is below 10, make the PH adjustment and then bring the FC back up to SLAM level. You can safely add bleach about 30 minutes after you add the muriatic acid so it shouldn't cost you much time during your SLAM. Here is the link to the SLAM process in case you need it. SLAM - Shock Level and Maintain - Trouble Free Pool

Thank you again for your help and additional information.