Help me understand Slam then to Mustard algae shock level

[OHcabanaboy]

I'm not sure if this belongs here or in the chemistry section so if it doesn't belong here, moderators please move to the appropriate place.
I've been reading about the method for getting rid of mustard algae. From the different discussions here it appears you are supposed to bring your pool first to "slam" or shock level until you get a OCL test of less than 1ppm then raise to mustard shock level. I guess I'm curios why? Why not just get to mustard algae shock level and hold it there? Is the elevated shock level something that could harm a vinyl liner? I would think bringing to levels needed to kill the M.A. would be the starting point. I'm just trying to learn a bit more about the how and why of the things we do.

For example, My pool at
cya 40
ph 7.5
Bor 15
TA 150

Calls for a shock level of 16 but a mustard algea level of 24. So why not just go to 24, hold until you have the appropriate OCL and CC results and then let it come down to normal FC, do a PH reading and call it a day?

 

[kimkats]

The risk to liner and equipment is not worth holding the MA level for very long.

Kim:cat:

 

[OHcabanaboy]

So the theory is to get it on the ropes with shock level then deliver a short finishing blow with MA level. Luckily I have never experienced a bloom that required much more than 48 hours to clear but after reading was wondering why the step up. What got me wondering was another poster had mentioned they had passed a OCLT and had CC of zero but was going to up to MA level. I thought once you passed OCLT and CC's were no more than .5 ppm all was well. But I must have thought wrong.

 

[AimeeH]

In all honesty, true mustard algae is somewhat rare. It seems more like a lot of people "think" they have it because algae keeps coming back. When in reality the algae that keeps coming back is due to a missed step in proper maintenance of chemical levels.

That's been my own observation from years of reading threads as well as my own pool care experience.

 

[kimkats]

So the theory is to get it on the ropes with shock level then deliver a short finishing blow with MA level. Luckily I have never experienced a bloom that required much more than 48 hours to clear but after reading was wondering why the step up. What got me wondering was another poster had mentioned they had passed a OCLT and had CC of zero but was going to up to MA level. I thought once you passed OCLT and CC's were no more than .5 ppm all was well. But I must have thought wrong.

You thought right. That poster wants to do that and it will not hurt anything if they do so..........If it makes them happy....

Kim:cat: