It’s been a while since slamming

[carl292]

Hi all,
I need to slam my pool. Started going green on the walls and corners.

Few years back I slammed with the old pool calculator here. Which I still have. With the new mobile app the suggested FC target level is different. The older calculator has 2 suggested FC fields at the bottom shock and mustard algae values. Shock is 16 and mustard algae has 24 (??).
Now the mobile only has target slam FC value 16.
Not sure why the calculators are different with the same inputs and the mobile only has one slam value. I thought I should use the mustard algae 24 because it’s algae, right? Or am I shocking. Which should I be using?
Thanks everyone

 

[beemerbob]

Now the mobile only has target slam FC value 16.
Not sure why the calculators are different with the same inputs and the mobile only has one slam value. I thought I should use the mustard algae 24 because it’s algae, right? Or am I shocking. Which should I be using?
Thanks everyone

I'm assuming your CYA is 40. FC of 16 is the value to use until you get clear water with no sign of algae, CC<0.5, and pass the overnight test. Then raise to the mustard algae level for 24 hours. I thought that was FC 20 for CYA of 40, not 24. But regardless, that's the reason for the MA number.

 

[Donldson]

I thought I should use the mustard algae 24 because it’s algae, right?

Mustard algae is a specific type of chlorine-resistant algae. That level is only supposed to be used when all signs indicate the problem is that specific species of algae.

SLAM stands for Shock Level And Maintain. The old calculator has been around since we called it the "Shock Process" but it was too confusing since pool stores and industry members use that term for so many different things and the site held a contest to come up with a better name. So the SLAM Process was named, and the 40% FC to CYA ratio is referred interchangeably as "shock level" or "SLAM level".

For a CYA of 40 your target has always been 16.