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GFO Granular Ferric Oxide (1 lb) - AquaMaxx


Item #: UJ1518

Temporarily Out of Stock

AquaMaxx Granular Ferric Oxide (aka GFO) is an adsorbent filter media that helps to remove phosphate from the aquarium water without leaching it back into the water.

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 media reactor for maximum efficiency, placed in a media filter bag and placed where water may 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 (1 - 3 month range)
  • Note: Alkalinity levels may drop when used, so should be monitored and adjusted as needed.

Available sizes: 1 lb / 2 lbs / 4 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
July 10, 2020

Yes, I would recommend this.

Good size

Very good product, and size

Was this review helpful? 0 0


Reviewed on
February 12, 2020

Yes, I would recommend this.


Good product

Was this review helpful? 0 1


Reviewed on
January 17, 2020

Yes, I would recommend this.

What phosphates?

Pros: Works well in reducing phosphates

Cons: Nothing.

I've been running Aquamax GFO for years and it simply works great. I tried other more expensive brands and didn't notice the difference so I'll stick with AM considering the value and quantity you receive.

Was this review helpful? 1 0


Reviewed on
December 25, 2019

Yes, I would recommend this.

It’s Gfo, gets the phosphates out

Pros: Takes out the phosphates

Cons: Need some kind of reactor and pump to tumble it for most effective use

Gfo works. Been using it for years in a small reactor with a pump to tumble it as a normal part of water maintenance. Phosphates and nitrates are always something you need to manage. This will definitely help on the phosphates.

Was this review helpful? 2 0


Reviewed on
December 06, 2019

Yes, I would recommend this.

Best GFO

Pros: Amazing product

Cons: None

In my opinion one of the best GFO options out there! Last super long, doesn’t breakdown as fast as others and gets the job done! I use about 9oz in my 120 gallon mixed reef and it last about 2-2.5 months!

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Reviewed on
September 24, 2019

Yes, I would recommend this.

Great GFO!

Pros: Good Price and Cleans up my Reef

Cons: None

Great quality GFO, I trust and use Aquamaxx myself in my Reef Tanks. A little goes a long way, very little dust. Rinses easy and helps keep my reef in check.

Was this review helpful? 1 0

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