PH during the SLAM

[AlStar250]

Hi guys thanks for your posts. I too have a filthy green pool that hasnt had chlorine in it for probably 1 month (estimate). My kit is a TF-100 and the first thing I wanted to do chemical wise was adjust PH as your recs say it's unreliable once I start the SLAM. I adjusted it down per your recs to 7.5 with Muriatic acid and then started the SLAM using nothing but good 12.5% SH. My question is am I done with the PH balance? Or is there a point when the chlorine gets down to a certain level, which undoubtedly it will several times I'm sure, do I then recheck and readjust? I am headed to buy a bit of DE to add to my sand filter as well.

Also with a CYA of 70, my FC goal is 28. How often do I add chlorine to get it to that level? I started with 3 gallons of SH and will recheck in an hour

God what a mess this pool is right now, but I trust the process and look forward to hearing what you guys have to say. Thank you!

 

[Texas Splash]

We recommend adjusting pH between 7.2-7.4 because the elevated FC level of the SLAM will produce a temporary elevated pH rise when the FC is over 10. Once pH is adjust down, the SLAM FC level takes priority and there is no need to check pH again until after the SLAM. If a pool required a treatment by a SLAM for a very long time, perhaps 2-3 weeks for example, then it may not be a bad idea to let the FC fall to 10 or below just long enough to validate a true pH reading, then increase FC again to complete the SLAM.

As for the DE, just make sure to not add it to the sand until near the end of the SLAM, generally designed to pick-up the finer stuff left behind at the end of the SLAM. When your pool is green and full of algae, the DE will just clog-up things and require lot of babysitting as pressure will increase quite quickly.

In the end, do your best to maintain the proper SLAM "FC" level based on yoru current CYA, backwash when filter pressure increase by about 20%, and make sure to brush daily. Good luck on your SLAM!

 

[AlStar250]

Thank you that is great information. I edited my initial post to ask about recommended intervals for adding chlorine. I had 8 gallons of 12.5% SH and started with 3 after the PH adjustment. It says not to check FC more than once an hour, just not sure how often to add the chlorine. I'm kinda worried about when I have to go back to work and will be gone for 8+hrs

 

[Texas Splash]

In the early stages of a SLAM, it's not uncommon to re-check the FC (with your FAS-DPD power & drops) every hour or so. Once your pool adjusts to the SLAM and begins to overtake the young algae, you will see the FC holding better, so the timing pattern will back-off of the testing to longer frequencies. If you have to leave the house for work or something, don't try to elevate your FC way over your SLAM level in an attempt to keep it at the SLAM level. Stick to the assigned FC SLAM level based on your CYA. If it drops while you're away, simply increase it when you get back home. Hope that helps.