Unable to get rid of Mustard Algae

Mdragger88

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Jun 1, 2018
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Hernando, Ms
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The last 24 hours should be the elevated mustard algae shock level. Note, that if I'm reading the chart correctly that should be 40.5 and not 10.5.

The goal here is to give the mustard algae one last zap after you have finished the regular SLAM.
He’s referring to maintaining a higher min fc level after all is said & done.
 
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Mdragger88

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Jun 1, 2018
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Hernando, Ms
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Thanks for that. How long should I maintain the 10.5?
Possibly indefinitely. If you wish to maintain a lower fc you could lower your cya level (as 70 is high if you don’t have a swg) so u can get accurate ph readings or invest in a ph meter (they are unaffected by fc levels higher than 10ppm). Remember that on the FC/CYA Chart the normal minimum fc for your cya is a “Do Not Go Below” value - ideally you should maintain the top of the “Target” fc level so you never risk getting to /below min. So for 70 cya (in a chlorine pool) that would be 10 ppm anyway. MA maintenance minimums aren’t that much higher.
 

TJrubicon

Member
Feb 2, 2021
16
Woodland Hills, Ca
The last 24 hours should be the elevated mustard algae shock level. Note, that if I'm reading the chart correctly that should be 40.5 and not 10.5.

The goal here is to give the mustard algae one last zap after you have finished the regular SLAM.
I was wondering about the mustard FC min column, the 10.5. What is that for?
 

TJrubicon

Member
Feb 2, 2021
16
Woodland Hills, Ca
Possibly indefinitely. If you wish to maintain a lower fc you could lower your cya level (as 70 is high if you don’t have a swg) so u can get accurate ph readings or invest in a ph meter (they are unaffected by fc levels higher than 10ppm). Remember that on the FC/CYA Chart the normal minimum fc for your cya is a “Do Not Go Below” value - ideally you should maintain the top of the “Target” fc level so you never risk getting to /below min. So for 70 cya (in a chlorine pool) that would be 10 ppm anyway. MA maintenance minimums aren’t that much higher.

I see. I had actually drained about 80% of the water and refilled. The cya when I acquired the pool was in the 2 or 300s. Should have drained the entire thing, oh well hindsight is 20/20. I'll refrain from ever using tablets and I'm hoping to see the cya slowly decrease from splash outs and backwashing.

As of today did my morning scrub and didn't see any algae at all! I ran out of fas dpd and so I'm kind of blind to the chlorine but adding about 24 Oz cal hypo every other night. Once I get more reagent, I'll bump it up to 40.5 and then let is coast down to 10. My plan will be to raise levels to 10, and when it reaches about 6 I'll add more chlorine, giving me a a range of 10- 6.

Does that all sound OK? Really wish liquid chlorine was cheaper. Cal hypo is ~40-50% cheaper.
 

JJ_Tex

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Jul 17, 2019
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The minimum is exactly that, the bare minimum you ever want your FC to be without risking algae returning. I was a bit confusing in my post, but here are the steps that Mdragger is outlining:

1. Do a regular SLAM
2. After you pass the criteria to end the SLAM, go 24-hours at the elevated mustard algae rate
3. After that you are good to go back to normal. Mdragger is suggesting you target 10.5 on a go forward basis to make sure it does not return.
 
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TJrubicon

Member
Feb 2, 2021
16
Woodland Hills, Ca
The minimum is exactly that, the bare minimum you ever want your FC to be without risking algae returning. I was a bit confusing in my post, but here are the steps that Mdragger is outlining:

1. Do a regular SLAM
2. After you pass the criteria to end the SLAM, go 24-hours at the elevated mustard algae rate
3. After that you are good to go back to normal. Mdragger is suggesting you target 10.5 on a go forward basis to make sure it does not return.

Awesome! Thank you so much for taking the time clarifying that! I'm going to try to keep the levels above the minimum with the target being 10.5. Ideally I only have to tend to the pool 2x a week, as I've been unrealistically dedicating a lot of time to the slam process. Everything else has been on hold as a consequence.
 

Mdragger88

Bronze Supporter
Jun 1, 2018
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Hernando, Ms
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Vinyl
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I see. I had actually drained about 80% of the water and refilled. The cya when I acquired the pool was in the 2 or 300s. Should have drained the entire thing, oh well hindsight is 20/20. I'll refrain from ever using tablets and I'm hoping to see the cya slowly decrease from splash outs and backwashing.

As of today did my morning scrub and didn't see any algae at all! I ran out of fas dpd and so I'm kind of blind to the chlorine but adding about 24 Oz cal hypo every other night. Once I get more reagent, I'll bump it up to 40.5 and then let is coast down to 10. My plan will be to raise levels to 10, and when it reaches about 6 I'll add more chlorine, giving me a a range of 10- 6.

Does that all sound OK? Really wish liquid chlorine was cheaper. Cal hypo is ~40-50% cheaper.
Be sure to meet all 3 end of slam criteria @ normal slam levels before moving on to the MA protocols
D682A555-9A24-4528-A1D4-B95F40EE7B16.jpeg
Then I would suggest you maintain the MA minimum of 10.5 - no lower. Higher is ok to allow for drifting down. Or else u may find yourself slamming again.
It is safe to swim anywhere between min & normal slam level for your cya.
"Yel/Mstrd Min" is 15% of the CYA level
If u maintain the MA min for a while you may be able to return to normal targets. Really its just trying it & seeing what happens - but I personally wouldn’t try it any time soon.
 

mknauss

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May 3, 2014
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Laughlin, NV
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Does that all sound OK? Really wish liquid chlorine was cheaper. Cal hypo is ~40-50% cheaper.
Check your CH. Your fill water is high in CH to start. Your use of CalHypo will most likely require you to drain more water soon.
 
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Mdragger88

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Jun 1, 2018
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Hernando, Ms
Pool Size
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Lowering the cya to about 50 would probably really benefit you as well. I would imagine that the abundance of cya (making maintaining the appropriate fc level impractical) is what allowed the algae to take hold in the 1st place.
 

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TJrubicon

Member
Feb 2, 2021
16
Woodland Hills, Ca
I am on day 14, Still see tiny amounts just in one section of the pool. Have been keeping the chlorine at or above the SLAM protocol, overnight chlorine loss is 0.5 and 0 CC. Man, i am over this. How would a pool man or pool company have done this? There's no way anyone would be doing what I am doing for this stinking pool.
 

CrystalRiver

Well-known member
Jun 19, 2020
533
Massachusetts
A pool company would dump a ton of chlorine in all at once, risking damage to equipment, but hey it's not their equipment what do they care. Or they tell the owner that they have "chlorine lock" and tell them to drain and refill. Or they blame it on pollen or something else.
 
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TJrubicon

Member
Feb 2, 2021
16
Woodland Hills, Ca
A pool company would dump a ton of chlorine in all at once, risking damage to equipment, but hey it's not their equipment what do they care. Or they tell the owner that they have "chlorine lock" and tell them to drain and refill. Or they blame it on pollen or something else.

Ehh, I can see why, this amount of work is pretty unrealistic. Imagine having multiple properties. How do hotels do it? Just keep chlorine higher than recommended?

My free chlorine drops about 1.5 per 24 hour period. I dont think I have a ton of algae eating up my chlorine.
 
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