NA Advanced Co2 Reactor | Advanced Version With By-pass Valve | Clear Reactor Chamber

(5 customer reviews)

Advanced CO2 Reactor for Aquariums | Free Shipping

This CO2 reactor for aquarium is one of the most efficient methods for diffusing CO2. It includes a clear reactor chamber so you can see the CO2 being dissolved.  In addition, the NilocG CO2 reactor is an advanced reactor with a bypass that is efficient for tanks well over 100 gallons. It also performs well with high flow filters such as fluval fx5/fx6.

This aquarium CO2 reactor is designed to be used between the canister filter and the tank on the output side of the filter.  It should be mounted under the tank and needs 18-24″ of vertical space.  Water should enter the top of the reactor and exit out the bottom.  If you have any questions about the use of the style reactor please make sure to contact us before purchasing.



Add Accessory Kit?

(Hose Clamps and Stainless Check Valve)

2″ PVC pipe straps to mount reactor to wall or aquarium stand

Needed For fx4/fx5/fx6 ribbed tubing


NA Advanced CO2 Reactor

The major advantage of this aquarium CO2 reactor, other than almost 100% dissolution of CO2, is that they require almost no maintenance at all while nothing remains visible in the tank.

Before placing an order, please make sure to choose the tallest size NilocG CO2 reactor that you can fit under the tank. The taller/longer the reactor, the more efficient it is in dissolving the CO2. Also, make sure you confirm the inside diameter of the output tubing on your filter.

The actual length of the reactor will be +/- 0.5″. If you have a very tight fit, please let us know before you place your order.

Note:  For higher flow filters which use 1″ tubing such as the fluval fx5/fx6 filters, the 24″ long reactor is highly recommended.  This version, in addition to the 22 is also recommended for anyone using the fx4, as a longer reactor can handle a higher flow.

Color of the aquarium CO2 reactor:  The standard color for the CO2 reactor for the aquarium is black. It can be painted in another color upon request, for an additional cost. If you would like a different color, make sure to check that option above, and include your preferred color in the comments section before completing your order. Please choose standard colors only. We cannot guarantee the exact match of the color will be achieved.

Setup Instructions:


  • Mount the aquarium CO2 reactor vertically (long side up)
  • The water should enter the top and exit the bottom
  • Start with the valve closed (parallel to the ground)
  • When all the hoses are connected (filter and CO2) run the reactor for 24 hours before making any changes
  • If after 24 hours you are getting CO2 bubbles out of the return pipe, open the valve slightly, then wait for another 24 hours
  • Repeat the previous step until you are no longer getting CO2 bubbles pushed out of the reactor



*Shipping for Rex Grigg CO2 reactors is via FedEx or USPS ground shipping.

*The Rex Grigg CO2 reactor will be shipped a week later as it is a custom build piece.

Additional information

Fitting Size

1/2"(12mm), 5/8"(16mm), 3/4"(19mm), 1"(25mm)

Reactor Length

24" Tall, 22" Tall, 20" Tall

5 reviews for NA Advanced Co2 Reactor | Advanced Version With By-pass Valve | Clear Reactor Chamber

  1. Ian (verified owner)

    This reactor does exactly what it is supposed to – CO2 is completely dissolved in the reaction chamber before it enters the aquarium. Much more efficient than a diffuser. My 24″ version is hooked up to a Fluval FX6. Attaching the reactor to the filter was a breeze – just be careful to check for leaks at the attachment points between the reactor and filter hose. Initially I re-used an older rubber connector and it leaked even with hose clamps. The problem was fixed when a new connector was used. The reactor itself works flawlessly. Great customer service as well.

  2. Dan (verified owner)

    100% dissolution. Works perfectly, adjust the valve until you see no more bubbles from your outflow and you know all the CO2 is being dissolved. It is solidly built, honestly probably better than I could have done myself. You may be able to build it cheaper yourself, but you have to find your own parts, paint them, put them together so they don’t leak etc… In the end it came down to convenience and quality, and buying this reactor has both. Would recommend buying the largest reactor, I have it on a 30 gallon tank now, but you can move it to a larger tank in the future and know you’re covered. To sum it up, I say buy it and enjoy having the best prebuilt reactor available.

  3. Ivan (verified owner)

    The Na Adv. Reactor is a must for your planted tank.No soda bubbles,great diffuser,minimum maintenance,semitransparent middle tube for bubble counting.Love it!

  4. Matt Wohlford (verified owner)

    I’ve dabbled with different forms of co2 dispersion including diffusers, atomizers, and even a smaller reactor. This Reactor hits the mark. I have this setup on my 55 gallon planted tank. I would recommend buying the longest length if possible (I went with the 24″ tall version) and I have absolutely no co2 bubbles coming into my tank -so there is some quality diffusion going on.

    It is also nice that middle tube is semitransparent, you can make out the co2 bubbles being injected, so you don’t really need to use a bubble counter. It would easier to see if the tube was clear, as it would be easier to count, but this is a minor complaint.

    Build quality is solid.

    No regrets with this purchase, it should “travel” around to many different tanks for many years to come.

  5. Ryan Alfredo

    Up until this point, I have been using the atomic atomizers to diffuse CO2 into my aquariums. These work great but I found that I was wasting CO2 in the form of bubbles which rise to the surface and pop. Also, the bubbles make the water look like soda water, which I like, but it does cut the visibility down and taking a clear picture of the aquarium is impossible unless you shut the CO2 off.

    I got a 150-gallon tank and decided to try something new regarding CO2 diffusion. I found out about this reactor (ADVANCED CO2 REACTOR) and decided to give it a go. Colin from NilocG aquatics was fantastic. He helped me get set up and answered all my questions.

    This device literally diffuses the bubbles into the water until there is no bubble left. The only bubbles you will see are the oxygen bubbles streaming from your plants. Had I not seen the bubbling plants, I would not know there was co2 in the tank! This makes it 100% efficient and allows me to lower my bubbles per second significantly.

    I used to have to disconnect my old atomic diffuser from my filter tubing every few months to clean the clogged ceramic pores. I don’t think this device needs any kind of maintenance so that is a HUGE plus. That was always a real pain. I am happy to cut that out of my routine.

    The clear nature of this reactor is nice because you can see if bubbles are getting close to the bottom(exit) and open the valve a bit to ease the water pressure a bit and keep all bubbles in the reactor until fully diffused. Being able to see this happen before my eyes is fantastic!

    Honestly, I am thinking of adding these devices to my other aquariums eventually so I don’t have to run through as much co2. I would recommend this to anybody looking to get more efficiency out of their pressurized system and lose the soda water look. It is fantastic!

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