Updated: September 14, 2022 - By: - Categories: Reef aquarium

Using a media reactor will enhance the water quality of your saltwater tank. They might not be essential but are a good addition to your aquarium equipment. A clean healthy tank means happy fish! In this article, we will learn more about this equipment and list some of the best media reactors for your benefit.

Media reactor comparison table

Model Our rating Dimensions Media capacity Flow rate Application Hosing
Innovative Marine Minimax Pro editor's ratingInnovative Marine Minimax Pro #ad 2″ x 2.3″ x 11.75″ 150 ml 10-52 GPH (pump included) nano tanks 10-20 gallons not use (pump connects directly to the reactor)
Two Little Fishies Phosban Filter Media Reactor editor's ratingTwo Little Fishies Phosban Filter Media Reactor #ad 3″ Diameter x 14″ H 385 ml 20-30 GPH up to 150 gallons 1/2 inch (12.7 mm) ID (buy separately)
Accel Aquatics FR-30 media reactor editor's ratingAccel Aquatics FR-30 media reactor #ad 5.5″ Diameter x 15.5″ H 600 ml 150-400 GPH large reef systems 1/2 or 3/4 inch ID (not included)
AquaMaxx FR-SE GFO Hang-On Media Reactor editor's ratingAquaMaxx FR-SE GFO Hang-On Media Reactor #ad 3.2″ Diameter x 14.6″ H 1000 ml 150-300 GPH 50-150 Gal 1/2 inch
Aquatop MR-20 Multimedia Reactor with Pump editor's ratingAquatop MR-20 Multimedia Reactor with Pump #ad 2.4″ Diameter x 15″ H 95 GPH (adjustable) 10-75 Gal 1/2 inch
QANVEE Fluidized Moving Bed Filter editor's ratingQANVEE Fluidized Moving Bed Filter #ad 8.8” × 3” × 4” moving bed filter media air pump powered 20-50 Gal, freshwater air hose
Reef Octopus Beginner OCT-MF300B editor's ratingReef Octopus Beginner OCT-MF300B #ad 2.5″ Diameter x 15″ H max 95 GPH (OTP 300 water pump included) up to 150 gallons included
Lifegard Aquatics R800128 Turbo Reactor editor's ratingLifegard Aquatics R800128 Turbo Reactor #ad 4.7″ L x 4.15″ W x 15.75″ H 450 ml 240 GPH (Quiet One 800 pump) 75-150 gallons not use (pump connects directly to the reactor)
Bubble Magus BP100 editor's ratingBubble Magus BP100 #ad 3.5″ Diameter x ” H 1500 ml 180 GPH (WP600 pump) up to 150 gallons not use

What is a media reactor?


A media reactor is a filtration device used in saltwater aquariums. It is a simple device that basically consists of a tube containing filter media. As water is forced through this equipment, it passes through the filter media inside and comes out purified.

A media reactor is much more effective in cleaning up aquarium water than putting a media bag in your tank or sump. Most media reactors are up-flow style, which is most effective. It means water is forced up through the bottom of the reactor, comes in contact with filter media for a certain duration, and comes out purified from the top. This duration can be adjusted by controlling flow rates. The flow rate you use depends on the kind of filter media being used.

This equipment is generally more needed in saltwater tanks but can also be used in freshwater tanks as an additional filtration device.

Best media reactors reviewed

Innovative Marine Minimax Pro internal media reactor

Innovative Marine Minimax reactor is made of cell cast acrylic for long life. It is effective for nano reef tanks with sizes ranging from 10 to 20 gallons. There is a mounting bracket for easy installation. You can put it in the rear filtration panel of a nano reef setup without a sump.

Two chamber designTwo chamber design #ad

This media reactor has two chambers. To use, remove the inner chamber from the outer chamber. After removing the rubber cap from the inner chamber, pour in your media of choice. Fill media to recommended levels. The reactor tube can hold up to 150 ml of media. Replace the rubber cap and replace the inner chamber.

Thank to the two-chamber design, media may be changed while the pump is on. The pump is connected directly to the reactor, there are no hoses or disconnect valves needed. The pump can generate flow rates ranging from 10 to 52 GPH. Switch the outer chamber to adjust the water flow.

Try this media reactor for hassle-free operation. It is certainly value for money for small to medium-sized aquariums.

Two Little Fishies Phosban Filter Media Reactor (best and budget option)

Two Little Fishies media reactor is a good choice for tanks up to 150 gallons. It can hold up to 200 grams (385 ml) of Phosban or 5-inch height of other media like GFO. The entire column can be filled if you use only activated carbon. This reactor works on the up-flow principle for the most efficiency.


This reactor can stand upright in the sump or aquarium floor or be hung on the side of the aquarium. Once setup is done, connect the pump as per instructions using 1/2 inch (12.7 mm) inside diameter tubes. The recommended flow rate is 20-30 GPH.

If using Phosban media, wet it before putting it in the reactor to minimize dust evolution. After reassembling the reactor, allow it to fill for a few seconds and stop the flow. Direct the return hose to a bucket and let any air and dusty water flow out into it. Once the water runs clear, place the return hose into the aquarium. Adjust flow so that PhosBan granules tumble slightly because too much flow can grind PhosBan. As the water pushes upwards, clean water passes through the top dispersion plate and returns to the aquarium.

The product comes with accessories for assembly. Replacements are available directly with Two Little Fishies Inc. or any distributors that deal with pet products. It is the sponges that need replacement mostly. They are vital to the filtration process.

Accel Aquatics FR-30 media reactor

The design is such that it feeds water through the top of the reactor. This is in contrast to most other media reactors that use up-flow technology. However, the flow accelerator inside the reactor produces very high water turbulence. Furthermore, the inverted conical bottom design of this media reactor keeps the bio-pellets moving effectively. This gives maximum contact with water, helping to clean it up well.

Accel Aquatics FR-30 media reactor works well with bio-pellets as well as other filter media that require fluidization. It can hold from 50 to 600 ml of media. Media is filled through a port on the top lid. Once recommended level of media is filled in, close the top lid securely in place.

This multimedia reactor provides flexibility to the user to pick whichever media they want to. In addition to bio-pellets, you may use any other filter media like carbon or GFO in this media reactor. These media are equally effective.

There is no need for a high-power pump in this design. A smaller water pump is enough to provide good circulation. The design provides 400% more water movement compared to other up-flow fluidized media reactors. This is all due to the conical design. The set does not come with tubing or a pump. For lowering nitrates in your aquarium, this is a great choice.

AquaMaxx FR-SE GFO Hang-On Media Reactor

AquaMaxx FR-SE GFO Hang-on media reactor can hold 1000 ml of media. It is made of high-quality cast acrylic and is very durable. It can be used with carbon, bio-pellets, or GFO. With its compact form, it can be used in nano reef aquariums. However, its large chambers help serve bigger size aquariums ranging from 50-150 gallons. It is a multipurpose fluidized media reactor.

To use, insert your media of choice into the reactor and fit it up. When it is working, water is forcefully pushed through the bottom of the reactor. Water then travels through filter media for filtration. Finally, cleaned and purified water is pushed to the outlet at the top of the reactor and returned to the aquarium. The up-flow design helps to keep media suspended and evenly dispersed. This gives greater contact time between water and filter media for better filtration.

You need to adjust flow rates depending upon the kind of media used. For carbon or GFO media, keep the flow rate at 150 GPH. For Biopellets, a flow rate of 300 GPH is recommended. A ball valve (buy separately) would be needed for good flow control. Flow rates are important to set properly. Otherwise, filter media may be too vigorously churned and also get crushed.

This model has a hang-on bracket that holds inlet and outlet tubes securely in place. Note that the water pump and tubing are not included in the set.

Aquatop MR-20 Multimedia Reactor with Pump

This media reactor has a reverse water flow design for maximizing filtration. It is designed to work with various filtration media. You may use activated carbon, phosphate sponges, nitrate sponges, or other resin filter media. This gives a lot of choices to users. The amount of media you put in will be decided by what kind of media you are using. Each media has its own specifications.

To begin using, unscrew the top, open the top of the reactor, and pour media inside the media chamber. There are sponges included in the pack to help keep media in place. One sponge at the bottom of the media chamber followed by media and then capped off with another sponge on top. Now screw back the top of the reactor securely. You are all set to get the media reactor going. Keep an eye on the media to see that it is moving around satisfactorily to give maximum contact with water.

The package comes with a pump, inlet and outlet hoses, and other necessary accessories. This means there is no need to wait for accessories to arrive or to order separately. With the bracket provided, you may hang it in your sump directly or in the aquarium.

QANVEE LH-600 Fluidized Moving Bed Filter for freshwater

QANVEE LH-600 equipment is not truly a media reactor but works on the principle of a fluidized bed. It is a good choice for freshwater tanks of up to 50 gallons.

This media reactor works with an air pump. After assembly, connect it with an air pump by an air tube and your reactor is ready to be lowered into the aquarium. There are four suction cups provided to help the reactor stay in place within the aquarium.

When the air pump is on, it injects air to the reactor chamber constantly. This helps to aerate the water flowing through the reactor as well as the media inside it. Oxygen-enriched water facilitates the growth of helpful nitrifying bacteria on the surface of the moving bed filter media. These helpful bacteria help to eliminate harmful ammonia and nitrite from your aquarium water.

Reef Octopus Beginner OCT-MF300B Media Reactor

This is a ready-to-use media reactor that has everything except for filter media. The pack includes a pump, hose, and fittings. The OTP 300 pump achieves a max flow rate of 95 GPH. There are double containment plates with sponges to keep filter media in place.

It is very easy to set up and use. It can be hung easily on the wall of a sump tank, internally or externally. It works fine with many types of filter media including GAC (granular activated carbon) and GFO. Depending upon what media you use, it works for systems up to 150 gallons. There is a 1-year warranty on both pump and reactor body.

Lifegard Aquatics R800128 Turbo Reactor with water pump

This high-quality media reactor from Lifegard Aquatics will be a good choice for your aquarium. The corrosion-resistant ceramic bearings make it durable and resistant. The most specific thing about this reactor is it produces a unique spiral flow while operating. This keeps filter media constantly moving and prevent them to clump, thus accelerating filtration.

When use with bio-pellets, it is very effective to encourage the growth of nitrate and phosphate-reducing bacteria. This helps in lowering phosphate and nitrate levels and preventing slime algae as well as other nuisance algae. With a small footprint, it will take up less space in your sump.

The design helps in easy maintenance. Simply unscrew the top cover to change or add media inside. It can hold up to 450 ml of media. Made with high-quality acrylic, it is suitable for use with many types of media like bio-pellets, GFO, carbon,…

Bubble Magus BP100 Media Reactor with pump

Bubble Magus BP100 media reactor is made of polished cell cast acrylic, which makes it durable as well as sturdy. Even with use in saltwater aquariums over a long time, the body does not become brittle. It has a media capacity of 1.5 liters. It works well with reef aquarium systems up to 150 gallons.

This reactor allows the use of different media like granular activated carbon, GFO, or bio-pellets. Depending upon the media used, the installation of the reactor will differ as per the instruction from the manufacturer.

The pump is located under the body of the reactor. This is a space-saving design for use in both the aquarium as well as the sump. It pulls water in forcefully through the bottom of the reactor. The up water flow is very effective in preventing filter media to settle and compact at the bottom of the reactor tube. This maximizes the filtration efficiency.

This reactor is easy to maintain. There are four screws each on the base as well as the lid. Opening either set of screws, you can clean or change media as needed.

Media to use in media reactors

Granular Ferric Oxide

Kolar Labs GFO HC Bayoxide Phosphate RemoverKolar Labs GFO HC Bayoxide Phosphate Remover #ad

Kolar Labs phosphate remover is an effective high-capacity ultra-pure virgin GFO (HC GFO). It is exceptional for phosphate removal. It also helps to remove arsenic, silicates, and heavy metals. It can be used in media reactors, filter socks, filter cartridges, and canister filters. Wash the media thoroughly to remove dust before use.


Kolar Labs Metabolix Bio-PelletsKolar Labs Metabolix Bio-Pellets #ad

These bio pellets are made from pure PHA resin made from corn. They are manufactured to slowly release a digestible carbon source for helpful bacteria to grow and colonize. These helpful bacteria then will help to reduce nitrate and phosphate levels in the aquarium.

Activated carbon

Kolar Labs Activated CarbonKolar Labs Activated Carbon #ad

This Kolar Labs activated carbon has fast action and helps to fix cloudy aquarium water, bad odors, and unwanted colors in your aquarium water. This product is in the form of granules and can be used in many types of filters including reactors, media bags, filters, filter cartridges,… Granules have optimum pore structure to suit aquarium usage.

Magnesium Media

Brightwell Aquatics NeoMag Magnesium Media for ReactorsBrightwell Aquatics NeoMag Magnesium Media for Reactors #ad

This magnesium media can be used in media reactors to supplement magnesium for coral growth. It gradually releases and maintains magnesium levels in reef aquariums.

Calcium Media

Brightwell Aquatics CoraLazarus - Calcium Media for ReactorsBrightwell Aquatics CoraLazarus - Calcium Media for Reactors #ad

This calcium media can be used in media reactors to supplement calcium for coral growth. It gradually releases and maintains calcium levels and alkalinity in reef aquariums.

Frequently asked questions

Is a media reactor necessary?

Frankly, it is not essential to have a media reactor in your aquarium. However, it is an effective filtration device that adds value to your already existing filtration options. A media reactor is largely pocket-friendly and helps to keep the water clean.

How to remove phosphate without a media reactor?

While a media reactor remains the most effective method of phosphate removal, there are other options as well. You can use specific phosphate removing agents like PhosGuard #ad, Phosban 150 #ad, Chemipure Elite #ad in a filter media sock and put the whole thing in a place where it gets strong-enough water flow for best results.

What is GFO media used for?

GFO (Granular ferric oxide) helps keep phosphate levels low, thus preventing algae. It can be used as a filter media in reactors, socks, cartridges, and other aquarium filters.

How much GFO should I use?

For GFO, start with 1 tablespoon for every 4 gallons of water (1 tablespoon per 8 Gal for HC GFO). After 4-8 weeks the aquarium will have adjusted to lower nutrient levels, ramp up to 2 tablespoons every 4 gallons (2 tablespoons per 8 Gal for HC GFO) until reaching your desired phosphate levels.

How often should I change GFO?

GFO should be changed depending upon the phosphate levels of your tank. Change GFO when phosphate levels begin to go up or when algae growth is seen. Commonly, you will need to change GFO every 4 weeks (8 weeks for HC GFO).

Can I use GFO without a reactor?

You can use GFO without a reactor but it will not be as effective. Rinse the GFO in a media bag and place it in your sump where the flow rate is high enough. It will work but not as well.

Can I put Purigen in a media reactor?

Purigen #ad is an organic resin used for filtration in aquariums. However, it is a small and light media and can get ejected with high water flow. In case Purigen is used, care needs to be taken to adjust the flow rate.

Can I use a media reactor for freshwater fish tanks?

It is okay to use media reactors if you have a freshwater aquarium. However, it is not essential if you have many aquatic plants in the tank. As you know, aquarium plants use nitrates and phosphates. No material filters phosphates better than plants in freshwater aquariums.

We enjoy keeping fish, and have for many years. We are trying to promote the hobby as much as possible. We want to see many others succeed in their fish keeping efforts and are committed to sharing our knowledge when we can.

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