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Yellow Out Swimming Pool Chlorine Shock Enhancing Treatment - 2 lbs.

  • Based on 1,702 reviews
Condition: New
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$19.19 Why this price?
4th of July Sale · 13% off was $21.99

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Availability: In Stock.
Fulfilled by Amazon

Arrives Monday, Jul 6
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Features

  • Compatible with pools operating a chlorine generator
  • Simple to use, requires no brushing, and cleans up algae gently without the use of harsh chemicals
  • Used in conjunction with pool shock to safely remove green, yellow, brown, and pink algae from your pool
  • Safe, non-toxic and can be used on all pool surfaces, including vinyl liners

Description

Use 2 lbs of Yellow Out per 15,000 gallons of water prior to shock treatment with an EPA-registered chlorine that kills yellow algae. Yellow Out works great for all pools, including those with salt chlorine generators and plaster finishes. Both of these circumstances can create a higher pH in pool water (especially newer plaster), which happens to be the ideal condition in which Coral Seas products work. The recommended pH level is 7.8 or higher for ideal performance. This is opposite of traditional algae treatment methods which require a lower pH for chlorine to be more efficient. Yellow Out are also not affected by higher levels of cyanuric acid.

Brand: Coral Seas


Item Weight: 2 Pounds


Item Form: Granular


Product Benefits: algae


UPC:


Brand Name: Coral Seas


UPC: 040053230375


Number of Items: 1


Unit Count: 32.0 Ounce


Model Number: FBA_YO-2#


Manufacturer Part Number: FBA_YO-2#


Manufacturer: Coral Seas


Item Type Name: Granular


Item Form: Granular


Product Benefits: algae


Item Weight: 2 Pounds


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Monday, Jul 6

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • Wow - This stuff works!
Wow - this stuff works! Followed the instructions & woke up to a much improved yellow algae attack. The next morning, the pool looked like new. This was my FIRST time using Yellow Out - pretty sure it won't be my last... AWESOME
Reviewed in the United States on April 22, 2026 by MarioF1

  • Best Algaecide
Yellow Out Swimming Pool Chlorine 2 lbs. works every time I get yellow algae. It arrived fast and is an excellent price.
Reviewed in the United States on May 2, 2026 by Ted V.

  • A Must-Have for Texas Pool Owners
iving in Texas, I deal with stubborn dark yellow algae on my pool walls every single year. It doesn't seem to matter how much work I put into keeping the pH and chlorine levels exactly right—the yellow spots always find a way back. This Yellow Out treatment is the only thing that actually works for me. When you follow the shock process described on the bottle, it cleans everything up completely. The best part is that I barely have to brush the walls at all; the chemicals do the heavy lifting, and the pool looks back to new in no time. If you’re tired of fighting mustard algae that won't go away with regular chlorine, this is definitely the solution. ... show more
Reviewed in the United States on January 7, 2026 by Fernando

  • Works either way twice the amount.
Works great but only when I used twice the amount.
Reviewed in the United States on October 27, 2025 by Bellajean

  • No more 'green' pool
In conjunction with 'regular' pool shock, this product knocked out our 'green' pool and cleared it up quickly! Very happy to have a clean, clear pool again.
Reviewed in the United States on May 27, 2026 by chris

  • Don't waste your money
Did absolutely nothing for my pool. Ended up purchasing stop yellow to clear the yellow algae we get every year at this time.
Reviewed in the United States on April 18, 2026 by Nicky G

  • Another later than advertised Prime delivery
Product and delivery is/was fine except it was 2 days later than advertised for prime members. This seems to becoming an Amazon trend...late deliveries.
Reviewed in the United States on May 14, 2026 by BLP Janocik

  • Works great
Works great
Reviewed in the United States on May 2, 2026 by Timmy Davis

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