Top 4 Reverse Osmosis (RO) Water Units for Marine Aquariums

Fish aquarium
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Using an individual reverse osmosis, deionization, or a combination RO/DI water filter unit to purify tap water sources before use in either fresh, brackish, or saltwater systems provides far superior water quality. These types of filters remove nitrate, phosphate and other chemical elements found in tap water that can lead to algae blooms and other problems. If you have a high level of contaminants in your tap water, a high-performance Reverse Osmosis unit for maximum filtration is recommended.

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    AquaFX Barracuda RO/DI Units
    AquaFX Barracuda RO/DI Units. Photo by PriceGrabber

    AquaFX Barracuda RO/DI Units are 4-stage RO/DI units which produce ultra pure water for aquarium hobbyists that demand the best. AquaFX Barracuda RO/DI Units adds another filtration stage to its premier water filtration technology for TDS rejection rates beyond 90%! Standard unit comes with a high efficiency, 1-micron sediment pre-filter (Stage 1), high-capacity chlorine and Volatile Organic Compound (VOC's) removing Carbon Block (Stage 2) and a special TFC/HI-S RO membrane (Stage 3). The RO...MORE membrane is a TFC sheeted element boasting high silicate rejection. Mixed bed DI resin filter (Stage 4) polishes RO water for ultra pure water of the highest quality.

    Available in 50, 100, 200 and 300gpd units.

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    Aquatic Life Reverse Osmosis Unit
    Aquatic Life Reverse Osmosis Unit. Courtesy of

    Updated design streamlines reverse osmosis (RO) and deionization (DI) setup and care. AquaticLife RO/DI units boast user-friendly features for professional tap water purification. Patented top-loading canister design allows easy cartridge access for routine checkups or scheduled replacement. 4-stage RO/DI unit employs a 1-Micron Pre-Filter Cartridge, Solid Carbon Block Cartridge, Thin-Film Composite (TFC) membrane RO Cartridge and a Mixed-Bed Resin Deionization Cartridge. Purifies tap water by...MORE removing most total dissolved solids and pollutants including heavy metal ions from tap water.

    The membrane can easily be back-flushed to extend its life. Available in 60 and 100gpd units.

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    Coralife Pure-Flo II RO Units
    Coralife Pure-Flo II RO Units. Photo by PriceGrabber

    Produce clean, pure water from chlorinated or non-chlorinated source water. Premium three-stage reverse osmosis (RO) units employ Sediment Pre-Filter Cartridge (Stage 1) for ultra-fine pre-filtration, Carbon Block Cartridge (Stage 2) for chlorine removal before reaching the TFC (Thin Film Composite) RO membrane (Stage 3) to effectively remove up to 98-99% of hardness, heavy metals, toxins, and many other impurities. Economical and easy-to-use reverse osmosis units are wall mountable. Does not...MORE require separate flush kit - simply switch the two outlet fittings.

    Available in 24, 50 and 100gpd models.

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    SpectraPure MaxPure RO Unit
    SpectraPure MaxPure RO Unit. Courtesy of

    The Spectrapure MaxPure MPRO Reverse Osmosis Unit efficiently removes water contaminants in 3 stages, with optional saddles and tubing it can be tapped into existing plumbing.