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GFO HC Granular Ferric Oxide High Capacity (1.5 lbs) - AquaMaxx


Item #: UJ1587

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AquaMaxx GFO HC is a high-capacity granular ferric oxide, highly adsorbent filter media that helps to remove twice the amount of phosphate from the aquarium water when compared to standard GFO.

Having GFO in your filtration system reduces the risk for nuisance algae growth, which can quickly build up as fish waste and leftover food breaks down.  Algae will get out of hand if left unchecked as high phosphate levels help to feed the algae, and also inhibit stony corals` calcium uptake to form new skeletal structure.

AquaMaxx GFO can be ran within a fluidized media reactor with a slow flow rate for maximum efficiency, placed in a media filter bag and placed where water may gently flow through it in the sump, hang-on-back filter, or canister filter.

Use Guidelines:

  • Rinse media before use
  • Use 1/2 a cup per 50 gallons of saltwater aquarium volume
  • Use 1/4 a cup per 50 gallons of freshwater aquarium volume
  • Test phosphates regularly and replace media when levels begin to rise (3 - 6 month range)
  • Note: Alkalinity levels may drop when used, so should be monitored and adjusted as needed.

Available sizes: 1.5 lb / 3.5 lbs / 6.5 lbs

Manufacturer information

AquaMaxx is a Southern California-based aquarium supply company that entered the market in mid-2008 with a line of affordable metal halide bulbs. The brand quickly gained recognition as word spread about the high quality and low cost of their lamps. In 2009, AquaMaxx released a line of aquarium filter socks and, in early 2010, unveiled an assortment of high-performance protein skimmer accessories and upgrades.

5 Stars


Reviewed on
March 03, 2020

Yes, I would recommend this.

Great at lowering phosphates

Pros: Easily gets phosphate to 0

Cons: None

Highly effective at reducing your phosphate levels to 0

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Reviewed on
November 23, 2019

Yes, I would recommend this.

Prevention is Best

Pros: Maintains Acceptable PO4 Levels

Cons: Requires Alkalinity Checks every now and then

In the reef keeping hobby, it always pays to utilize preventive measures, though these steps will initially, most of the time a little costly but, losing valuable corals will cost you a ton of money and frustration. Running a GFO gradually and safely lowers and maintains PO4 (Phosphate) levels to the ideal. This helps a lot when keeping dense livestocks, and dosing crucial additives. A healthy water movement, properly maintained and functioning protein skimmer, feeding moderation, regular filter cleaning and changes is required in conjunction with the use of GFO or any other reactors to lengthen the functionality and service life of the media.

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