How long to shock at MA level ?

tikifarmer

Active member
Oct 16, 2007
30
South Central PA
I had a mustard algae problem as well as a green algae problem in part due to getting my Liquidator dialed in . I began shocking at MA level (37) for my CYA level (65) last Thursday . There is a lot of dead algae (grayish /white) in the bottom of the pool that need to be vacuumed out at this point but , the water still is quite hazy ( I can see the drain and pattern on the liner 9' down ) and it does appear to be getting a little better every day . I read where it can take up to a week to filter out the dead algae . I have not performed the overnight FC loss test at this point but , my CCs have consistently been between 0 and .5 through this whole process . My question is how long must the MA shock level be maintained ? TIA for any thoughts ...
 

duraleigh

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I have not performed the overnight FC loss test at this point but ,
guidelines that most of us use for reaching the conclusion of the shock process are...

1. Your pool water is sparkling
2. Your CC's are .5ppm or less
3. Your overnight FC loss is not greater than 1.0

I think vacuuming in the filter position would probably be the thing to focus on next. Be sure to clean/backwash your filter as the psi increases from catching the debris.

I would keep high levels of chlorine in the pool until you meet all three criteria above. If you meet 2 & 3, you could logically conclude that filtration is your remaining task but if you fail 3, then you know you need to keep chlorine up high as well as filter.
 

tikifarmer

Active member
Oct 16, 2007
30
South Central PA
Thanks Duraleigh ...
Did the FC loss test last night and came up with 1 ppm loss / 0 CCs . Vacuumed yesterday and it is looking a bit better yet this morning as far as the haziness . I am going to keep the pump running 24 hrs a day until it is fully clear but , I am going to let the FC level fall back to normal levels .
 

frustratedpoolmom

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May 20, 2007
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SWSuburban Chicago, IL
For shocking to kill MA, we usually recommend maintaining your "normal" shock level until the FC loss is 1 or less, then bumping it up to the "MA" level for 24 hours. Be sure to treat any floats, toys, etc where it can lurk and check behind ladders, inside light niches etc.
 

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