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Seachem Onyx Sand 7Kg Aquarium Substrate

Marsoni M251S
Sale price$21.99
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Get it in 3 business days with 1 day shipping. Friday, May 29
Seachem Onyx Sand 7Kg Aquarium SubstrateSeachem Onyx Sand is a naturally dark grey sand that perfectly complements and enhances the appearance of any aquarium. It provides not only iron and other minerals but supports optimal KH levels for freshwater planted aquariums. Being carbonate rich, Onyx Sand provides an advantage to any plants able to utilize bicarbonates. Although ideally suited to planted aquaria, it may be used in any aquarium environment. Seachem Onyx Sand is most effective
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  • We offer a 30-day return/exchange service after receiving.
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4.5 ★★★★★
Based on 1571 reviews
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Sergio
Massapequa, US
★★★★★ 5
very good
Size: 7.5, Color: Cognac
veryyyy gooood
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Reviewed in the United States on January 29, 2026
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Coach Cynthia
New York, US
★★★★★ 5
Nice shoes
Size: 9, Color: Cognac
My Husband loves it 😍
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Reviewed in the United States on January 11, 2026
A
Verified Purchase
Alston 34 Paerdegat 14 st
Grantham, US
★★★★★ 4
I just need the size 12
Size: 12, Color: Tan
Gm.i made a mistake the first time when I order the size 13. I return it because it was to big .so I reorder a size 12 now am looking at my order they still sending me the same size 13 i will have to return it again because it is to big sorry I dont know what going
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Reviewed in the United States on May 8, 2026
R
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Rayan McLeod
New York, US
★★★★★ 3
Worth the price
Size: 10, Color: Tan
A little tie on the valley,
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Reviewed in the United States on May 20, 2026
T
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Thomas Micheal Bennett
Whiting, US
★★★★★ 5
Good
Size: 9, Color: Black
Good good good
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Reviewed in the United States on December 24, 2025

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