Diatomic Filters

Home fish aquarium
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Any freshwater aquarium owner who has had less than crystal clear water knows that conventional filters have their limitations. When faced with stubborn particulate matter or the dreaded scourge of green water, it's time to consider a diatomic filter.

The name comes from the use of diatomaceous earth, which has the effect of polishing the water to perfect clarity. Here are our top picks.

  • 01 of 03


    Vortex Filter

    Hands down, Vortex is the best. They've been on the market for decades, and have a well-proven track record. Although the manufacturer states this filter can be used continuously, I advise against it. The same high filtering capabilities also remove other constituents that are desirable. Use only for short periods of time to polish the water.

  • 02 of 03

    H.O.T. Magnum

    Hot Magnum Filter

    The H.O.T package is not a diatomic filter in the truest sense of the word because it does not utilize diatomaceous earth. However, the fine diatomic sleeve does remove most fine particles. It is easy to use, can be moved quickly from tank to tank, and has an optional cleaning attachment that is great for regular maintenance. For all around versatility, it's the best product you can buy.

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    Diatomagic. Diatomagic

    The Whisper Diatomagic is a compact, easy to use, self-priming unit. Although the throughput can't match Vortex, and it lacks the optional cleaning features of the Magnum, it still offers true diatomic filtering. If green water is your problem, this filter costs less than Vortex and will get the job done.