Good filtration is key to any aquarium as it keeps your water and fish healthy.
If your filter isn’t powerful enough or is struggling to effectively clean your tank, then disastrous consequences can occur.
A media reactor boosts filtration in your aquarium so you don’t need to worry about dirty water, while a GFO media reactor does this with the added bonus of reducing algae outbreaks and phosphate levels.
To help you find the right GFO reactor for your aquarium…
I’ve reviewed a variety of different products and analyzed their highlights and negatives.
Let’s take a quick look at all our top picks…
Made from high-quality cell cast acrylic and is designed for use with granular ferric oxide, bio pellets, and carbon. A pump with a flow rate of 52 GPH is included with the reactor.
Out of all the media reactors I’ve reviewed, this one is my overall recommendation.
Innovative Marine media reactors are both reliable and efficient. They conveniently come with a pump that has a flow rate of 32 GPH (gallons per hour), so there is no need to purchase one separately.
Best on a Budget
This media reactor is a solid choice if you’re on a budget due to its affordability.
The AquaMaxx FR-SE unit is a good-quality but relatively inexpensive choice for your tank. It has a compact design that allows for maximum contact time between your media and tank water.
My personal favorite reactor for an aquarium. It’s a little pricier than some of the other media reactors I’ve reviewed but it delivers in quality.
AquaMaxx’s Fluidized reactor is extremely durable and well-made. Its design ensures your filter media and aquarium water are given maximum contact time. This improves its effectiveness.
What Is an Aquarium Media Reactor?
A media reactor is essentially an advanced filter that improves filtration in your tank. It has a tube-like design that allows water to easily move upwards through it before being deposited back into your aquarium.
It’s a lot more efficient than a regular filter as there’s more surface area to allow for better contact between water and the unit itself. If your aquarium is frequently suffering from crashes or lacks filtration, then a media reactor is definitely worth considering.
What Is GFO?
GFO is an abbreviation for Granular Ferric Oxide, which is a reddish-brown powder that is compacted into granules. This powder hinders algae growth by removing phosphates in your tank. Low phosphate levels help steer off algae outbreaks and manage growth.
What Is a Granular Ferric Oxide Reactor?
Granular ferric oxide is a chemical filter media that is used alongside a reactor. This type of media is beneficial in reef tanks as it inhibits algae growth and removes phosphates.
Aquarium Reactor Media
There are a few different types of media that are commonly used in reactors. These include granular ferric oxide, carbon, and biopellets. Here I’ll briefly explain what these types of media are and what they do.
Granular Ferric Oxide
Granular ferric oxide is a powder that hinders the growth of algae by binding the phosphates it needs to grow. It is also an effective method for reducing phosphate levels in your tank for this reason.
Activated carbon is a type of chemical filter media that’s used for removing pollutants like tannins, chlorine, heavy metals, and bad odors from your aquarium.
Biopellets are a biodegradable polymer that act as food for beneficial bacteria to help with growth and thrivability. Unlike the other types of media used in reactors, biopellets are purely used to feed good bacteria.
How Long Does It Take for Granular Ferric Oxide to Work?
The length of time it takes for granular ferric oxide to start working depends on the type used and the amount of phosphates/algae in your tank water before you added the media.
Normally, you should expect to see lower phosphate levels overnight but they can sometimes take longer. A reduction in algae, however, isn’t usually as quick. It’s best to manually remove algae yourself as granular ferric oxide inhibits growth rather than directly destroying it.
How Much Granular Ferric Oxide Should I Use?
The amount of granular ferric oxide you use is open to interpretation, but a common dosage is to use ½ a cup of the powder for every 50 gallons of water (and no more than ½ a cup for every 25 gallons of liquid). For example, if you have a 100-gallon tank, then you’ll need around a cup of granular ferric oxide.
It’s best to use small amounts of granular ferric oxide at first and replace it more regularly. Over time, you can gradually increase the amount you use.
Avoid using excessive amounts of granular ferric oxide as doing so can remove phosphate from your tank too quickly. This can stress out your fish and cause damage to your coral.
How Often Should You Change Granular Ferric Oxide?
How often you change granular ferric oxide depends on your phosphate levels. If the amount of phosphates in your tank water starts to rise, then it’s time to replace your granular ferric oxide powder.
Most aquarists change the media every 4 to 8 weeks, though some replace it more frequently than this.
Does GFO Remove Nitrates?
Granular ferric oxide doesn’t remove nitrates from your tank water, only phosphates. If you want to lower your nitrate levels, you’ll need a different type of product like a nitrate reducing solution or conditioner.
How to Install Reactors
Setting up a media reactor is slightly different depending on the model, but there are a few basic factors for assembly that they all share.
- Find an appropriate placement for your device. Some units are designed to go inside in your tank, while others are designed to hang on the back of your aquarium.
- Check the tubing and make sure it is attached properly. Some reactors come with tubing, but some don’t. Either way, it’s a good idea to stock up on extra tubing just in case.
- Connect the intake tube to the pump on the unit, then put the pump inside your aquarium.
- Next, affix the output tubing to the unit. If you’re using a sediment filter, you should put it at the end of the output tubing.
- Take the lid off the unit and fill it with filter media.
- Place the sponges and strainers below and above other filter media.
- Place the lid back on the device and switch on the pump. That’s all there is to it!
Maintaining your reactor is very important for ensuring it works effectively and to its full potential. You should clean the pump, intake, and impeller with water every few weeks.
Additionally, make sure you rinse out the sponges and strainers regularly to prevent them from clogging up. Remember, never use soap or detergent when cleaning your media reactor or any aquarium equipment.
Aquarium Media Reactors Reviews
Made from high-quality cell cast acrylic and is designed for use with granular ferric oxide, bio pellets, and carbon. A pump with a flow rate of 52 GPH is included with the reactor
The Innovative Marine media reactor’s unique design minimizes the need for ball valves, thumb screws, flexible tubes, and PVC pipes that are normally associated with other reactors. This is great as it helps cut down on clutter and keeps space around your aquarium tidy.
The unit is made from high-quality cell cast acrylic and is designed for use with granular ferric oxide, bio pellets, and carbon. A pump with a flow rate of 52 GPH is included with the reactor, which is handy as you don’t need to purchase one separately.
The device is energy efficient and features a dual chamber for responsive flow control and simple maintenance. The internal chamber acts as a removable cartridge, this is really helpful as it allows you to quickly slide it out and drain liquid.
I really like the small footprint of the reactor as it makes it easy to place directly in sumps or conceal behind your tank.
One gripe with this reactor is the durability of its pump, which can be prone to breaking prematurely.
- Dimensions: 11.4” x 2.3” x 2.2”
- Weight: 1 lb
- Pump Flow Rate: 52 GPH
- Unique and compact design
- Energy efficient
- Easy to clean
- Features a dual chamber
- Includes pump
- Pump can break prematurely
Best on a Budget
AquaMaxx’s FR-SE hang-on filter media reactor is a great choice if you’re on a budget due to its affordability. The up-flow design of the unit helps keep filter media suspended and evenly dispersed to allow for maximum contact time between your media and tank water. This boosts its efficiency.
I really like the appearance of this reactor as it looks a lot more expensive than it actually is. I also appreciate the large size of the chamber capacity.
However, this reactor doesn’t come with tubing or a pump, so you’ll need to purchase these separately. In addition to this, the unit can get clogged quickly.
- Dimensions: 17” x 11.” x 6.3”
- Weight: 1.8 lbs
- Chamber Capacity: 0.26 gallons
- Pump Flow Rate: N/A
- Visually appealing
- Large chamber capacity
- Doesn’t come with tubing or pump
- Can get clogged easily
My personal favorite media reactor is this one from AquaMaxx. It’s available in two sizes; standard and extra large.
The unit is capable of running a few different types of media and is designed to keep your media suspended and evenly dispersed. This makes sure your media has maximum contact time with your aquarium water for optimal performance.
AquaMaxx’s Fluidized reactor is made from polished acrylic that’s durable. To make sure the filter is reliable for a saltwater tank, it has been rigorously tested in saltwater environments.
Unfortunately, the device doesn’t come with tubing or a pump, so you’ll need to buy them separately.
- Dimensions: 16” x 6” x 6”
- Weight: 3 lbs
- Chamber Capacity: 0.18 gallons
- Pump Flow Rating: N/A
- Available in a standard and large size
- Doesn’t come with tubing or pump
The filter is made from acrylic and is suited to both saltwater and freshwater tanks. Designed to achieve the most efficient use of PhosBan or other types of chemical filter media.
Next up is this reactor from Two Little Fishies. It’s designed to achieve the most efficient use of PhosBan or other types of chemical filter media.
Water is introduced at the bottom of the filter before being pushed upwards through the dispersion plate. This evenly presses the water through your filter media for prime effectiveness.
The filter is made from acrylic and is suited to both saltwater and freshwater tanks. It has connections for 0.5-inch hoses, as well as flexible fittings for the inlet and outlet making it easy to install and use.
The device can hold up to 5 inches of filter media or 200 grams of PhosBan, which is a bonus!
One of the main downsides of this reactor is its durability, which can sometimes result in leaking. You also don’t get any tubing or a pump with the unit.
- Dimensions: Unknown
- Weight: 0.32 lbs
- Easy to install and use
- Can hold up to 5 inches of filter media or 200 grams of PhosBan
- Can leak
- Doesn’t come with tubing or a pump
Made from durable acrylic and can be placed on the back of your tank or directly in your sump. This reactor comes with tubing, a pump, and sediment discharge so you don’t need to purchase anything separately.
AquaTop’s media reactor is another solid choice for keeping your aquarium sparkling clean. It’s made from durable acrylic and can be placed on the back of your tank or directly in your sump. It’s easy to use and set up, which is a plus!
Ready to Use
This reactor comes with tubing, a pump, and sediment discharge so you don’t need to purchase anything separately. The flow rate on the pump is 132 GPH and it can also be adjusted to produce a lower or higher flow.
The chamber accommodates a range of different filter media like activated carbon and granular ferric oxide.
However, the pump for this reactor can be a little weak, so it might not have enough power for some aquariums.
- Dimensions: 23.5” x 6.5” x 6.5”
- Weight: 3.5 lbs
- Pump Flow Rate: 152 GPH
- Includes tubing and pump
- Flow rate on pump can be adjusted
- Versatile design
- Pump can be a little weak
Let’s take a quick look at all our top picks…
After looking at a variety of granular ferric oxide media reactors, I think the best one to use in your aquarium is the Innovative Marine Minimax Media Reactor. Its unique design helps reduce clutter as you don’t need ball valves, PVC pipes, thumb screws, and flexible tubes that are typically associated with other reactors.
It comes with a pump that has a flow rating of 52 GPH, which is a real bonus as you don’t have to pay out for one separately. Another great feature is the dual chamber which allows response flow control and easy maintenance. The only downside of the unit is that the durability of the pump could be improved.
Other Great Options
My other two recommendations are the AquaMaxx FR-SE Media Reactor and AquaMaxx Fluidized Media Reactor. Both are great choices for your tank, but the former is a little more affordable.
They are both designed to keep your filter media suspended and evenly dispersed. This improves their efficiency and performance. I really like the design on both of these devices, but I slightly prefer the overall style of the AquaMaxx Fluidized unit.
Unfortunately, both of the reactors from AquaMaxx don’t include tubing or a pump. You’ll need to purchase this equipment separately to get the reactors up and running. The FR-SE model also can have a tendency to leak.