The Fluval Nitrite Removal Pads are specifically designed for the 306/307 and 406/407 external filters to effectively reduce nitrite levels. The Fluval Phosphate Removal Pads are specifically designed for the 306/307 and 406/407 external filters, these pads are composed of a complex, interwoven infused resin with embedded phosphate removers, which effectively trap floating waste & debris for a clean and clear aquarium.
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