Yellow Mustard Algae Treatment

spacey

Member
Aug 7, 2022
23
Oklahoma
Pool Size
18500
Surface
Vinyl
Chlorine
Liquid Chlorine
I've got yellow mustard algae and probably green algae at the same time. I used Yellow Out, added two pounds of chlorine as it says on the label, circulated for two days, but then it rained for three days and overflowed the pool. I had added 15 pounds of 99% Sodium Dichloro-S-Triazinetrione Dihydrate before the rain, but now the chlorine levels are not on the scale so the rain must have diluted it to basically nothing.

Yellow Out + fiber cellulose has worked for me in the past (sand filter).

So I should basicallly start over right?

Should I add chlorine now, or wait until the cellulose fiber has cleaned up the color of the water and the dead algae in the pool? What I did last time was to keep brushing the dead yellow algae which was settled with flocculant towards the deep end so that the main drain can filter it through the cellulose in the sand filter. It took several days.

I know yellow algae eats up chlorine very quickly when it's alive, so should I wait a few days to add the chlorine or just start adding it now?

Hayward Pro Sand Filter 300 lbs., 20 gpm/ft with 3.1 feet area / Hayward Super Pump / in ground vinyl liner / 18,500 gallons / only two jets.

Thanks.


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How are you determining that you have yellow algae? Your picture doesn't show anything to indicate it.

What brand of Yellow Out did you use?

15 pounds of dichlor will have raised your CYA level 50 ppm. That's not going to help at the moment.

How are you testing your water and what are your current numbers? FC, CC, pH, TA, CH, and CYA?
 
How are you determining that you have yellow algae? Your picture doesn't show anything to indicate it.

What brand of Yellow Out did you use?

15 pounds of dichlor will have raised your CYA level 50 ppm. That's not going to help at the moment.

How are you testing your water and what are your current numbers? FC, CC, pH, TA, CH, and CYA?
I've had yellow algae four times now, due to chemicals not being balance for pool closing. The water had a sandy-looking beige color before the Yellow Out, I don't have a photo. The flocculant drops the suspended solids to the bottom but the color is brownish or beige/tan instead of green.

The Yellow Out and sanitizer are in the attached photos, I used 4 pounds of yellow out for 18,500 gallons which is slightly more than it says to use.

I am testing using test strips, I know I should get a testing kit, which one is recommended?
 

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Some of it came up again from the bottom. I assume I need to do the SLAM process. I don't have my test kit here yet so I decided to add 25 pounds of granules, but hold off on the additional Yellow Out.
 

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Hey and welcome.
I would stop adding stuff until we figure out the right steps.
Order the TFPro, choose the SLAM Option. If you have a saltwater pool, order the TFPro Salt.

Please answer these questions:
  1. What kind of filter do you have?
  2. Please post pictures of your equipment pad?
  3. Have you been running the pump during the FLOC addition?
  4. If you have a valve on the pump, what position has it been in?