Mustard again?

[JDFester]

Well, I have enjoyed 2.5 months of a trouble free pool, after fighting off a Mustard outbreak. However, I am now seeing what looks like the beginning of another one, in the form of small blooms forming on the *morning* shaded side of the pool at the edge of the ramp area from shallow to deep. (For a little bit of history, I had the same symptom when I bought the house, a year ago this week... didn't recognize it as mustard or even algae until it got nasty this June; regular chlorine (tabs at the time) kept it in check and it really just looked like dirt...)

Like last year, the chlorine levels are not dropping any faster than normal, I pass the OCLT, (assuming it is valid with the pump not running overnight, but running at least an hour after the night test and an hour before the morning test...), and the water is crystal clear. Is that possible with mustard algae present? Am I just being paranoid? (I would upload a photo, but I am out of space and cannot figure out how to delete prior used photos...)

If this is the start of another outbreak, or an indication that I didn't get it all last time, do I go straight to the Mustard Shock level, since I have clear water and pass the OCLT? I forget how long it took to come down to normal levels last time, but my wife has a pool party planned for Sunday; am I better off to maintain levels now and just brush/vac until next week and then SLAM? My CYA is a bit high (~55-60), so my Mustard shock FC would be at 35... How long do I have to keep it there? Am I rushing things?

Thank you in advance!

 

[BasicTek]

To remove your old photos to add a new one go to settings > attachments
Can you provide your full set of test results or at least FC/CC/PH/TA and I see your CYA
How is the circulation where you have the possible algae (I got mine on the stairs all the time.)
Mustard algae can come at anytime from what I read about it, I had it and took me a while to get rid of, but that was before I practiced TFPC.

 

[JDFester]

pH=7.8
FC = 5.0, will raise to 8.0 tonight, unless I need to go higher.
CC = 0.0
TA = 68
CH = 75
CYA = ~58

Should I raise the FC to the mustard min tonight, and do an OCLT at that level?

Not really sure how to judge the circulation in certain areas of the pool; can't really feel it moving except near the pump outlets; the area I get the blooms is just behind one of those, so I suspect its an area of lower circulation...

- - - Updated - - -

 

[JamesW]

If you want to avoid a full SLAM right now, you could try a fc/cya of 15% to 25% (about 9 to 15 ppm fc).

It's not as sure as a full SLAM, but it might work.

Looking at the pictures, it's probably mustard. I would go to 40% now.

You should be able to finish a SLAM and get to swimmable fc levels before the event.

 

[BasicTek]

If CYA dot is visible at 50 line but not at 60 line it should be CYA of 60, the lines are not scale and it shouldn't be in between. With CYA of 60 you target FC is 7-9 mustard algae if that's what it is will be more resistant to chlorine especially in areas of less circulation. Brushing is mandatory and should remove it quickly, it will appear to turn into a cloud if mustard. If there's not enough you may not see anything but it usually removes easily. Can you add a pic?


Edit: you guys are too fast what he said

 

[JDFester]

Using the numbers for CYA=60; pulled the 58 from pool store test that I had done to double check my own test results.

The blooms do brush away easily, and "poof" into little clouds that dissipate quickly; it definitely behaves like mustard. I was just confused as its not consuming chlorine. Does the chlorine have to be high enough (above the mustard min level) to start seeing it consume the chlorine?

Picture is in post above...

 

[JamesW]

That type of mustard does not consume a lot of chlorine.

 

[domct203]

If you have visible algae, the pool is not truly clear.

Start a SLAM.

Once the water is clear and free of any algae, dead or alive, passes the OCLT, and the CC is 0.5ppm or less, raise FC to mustard shock level for 24 hours. Remember, you have to pass all 3 criteria before your SLAM is complete and you go to mustard shock level.

Be sure to brush, brush, brush. No mercy, the fight is on and you're in it to win it.

 

[JDFester]

Got it. Raised to SLAM level this evening.