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Bio Ouster

Bio Ouster 4-in-1 Weekly Pool Care – Water Clarifier for Sparkling Clear Pools | Inground & Above Ground Pools | Eco-Safe & Pet Friendly | 16 oz

  • Based on 93 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Amazon
Arrives Friday, Aug 28
Order within 13 hours and 19 minutes
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Features

  • 4-IN-1 WEEKLY POOL TREATMENT One potent formula does what basic clarifiers can't. It supports crystal-clear water, helps with buildup, enhances filter efficiency, and works alongside your weekly pool care routine so your pool stays sparkling week after week.
  • SAY GOODBYE TO CLOUDY WATER Tiny particles, body oils, and lotions are too small for your filter to catch, which is what dulls your water. This formula gathers them into clusters your filter can collect, perfect for restoring clarity after storms or heavy use.
  • HELPS PROTECT POOL SURFACES Dissolved minerals in your fill water can leave unsightly marks on the surfaces of your pool. This formula gathers those minerals into clusters your filter can collect, helping keep surfaces protected all season.
  • EASY WEEKLY DOSE Less time maintaining, more time swimming! Start with a clean filter before your initial treatment, then add 1 oz per 5,000 gallons weekly directly to the pool water surface and run the pump for 1 hour. One 16 oz bottle lasts all season!
  • WORKS IN ANY POOL, FAMILY-FRIENDLY FORMULA Designed for inground, above-ground, and saltwater pools even spas and hot tubs. The naturally derived, eco-friendly formula is a great choice for households with kids and pets. Proudly made in the USA.

Brand: Bio Ouster


Item Form: Liquid


Product Benefits: Clears Cloudy Water, Improves Filter Performance, Prevents Stains, Removes Oils, Scum, Dirt & Grime See more


UPC:


Number of Items: 1


Brand Name: Bio Ouster


UPC: 850072900025


Number of Items: 1


Unit Count: 16 Fluid Ounces


Manufacturer: Bio Ouster


Model Number: OS-PCR-16


Manufacturer Part Number: OS-PCR-16


Item Form: Liquid


Product Benefits: Clears Cloudy Water, Improves Filter Performance, Prevents Stains, Removes Oils, Scum, Dirt & Grime


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Friday, Aug 28

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

    • Clean and clear water
Bio-Outsrer Oster 4-1 once a week care does a great job in keeping my above ground pool clean and clear, just once a week. It’s fabulous and I would buy it again.
Reviewed in the United States on July 24, 2026 by LA
    • Great Buy!
My pool was all cloudy and a little green, I used this and it cleared up with 1-2 hours! I love that it’s kid and pet friendly.
Reviewed in the United States on August 19, 2026 by Hailey
    • Great product
Completely clear water after the first use
Reviewed in the United States on August 5, 2026 by Jessi
    • Experience sharing
It keeps the water 💦 in good shape!
Reviewed in the United States on July 17, 2026 by Guy
    • Clear water!
Mase my pool go from cloudy to clear overnight! Only had to use a tiny bit for my 10x30. Will last all season! Very good price and extremely effective. Clear instructions, just like my water.
Reviewed in the United States on July 14, 2026 by The Raff
    • ...
No funciona...
Reviewed in the United States on July 31, 2026 by Jaime Ascencio
    • GREAT FOR POOL AND HOT TUB
NICE PRODUCT
Reviewed in the United States on August 12, 2026 by JMB
    • Excellent Results — Cleared Cloudy Water Fast
Review Image by Brittany K.
Review Image by Brittany K.
I ordered this for my 21,000-gallon in-ground pool, which is older and can be a bit difficult to keep perfectly clear. I had been dealing with ongoing cloudiness, so I decided to try this as part of my weekly pool care routine. After adding it and running the pump, I was genuinely impressed—the water was noticeably clearer by the next day. It made a bigger difference than I expected and helped bring the pool back to a clean, sparkling look quickly. I also appreciate that it’s made in the USA and marketed as kid and pet friendly, which gives a little extra peace of mind when using it around the home. I was impressed enough that I’ve already ordered another bottle. A great value. Pros • Cleared cloudy water quickly • Noticeable results within about a day • Easy to use in regular pool maintenance routine • Works well for larger pools (21,000 gallons in my case) • Made in the USA • Kid and pet friendly Cons • Results can vary depending on pool condition and filtration system ... show more
Reviewed in the United States on June 22, 2026 by Brittany K.

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