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GLA Aquarium CO2 Reactor 16/22mm

20 reviews Write a Review
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GLA Aquarium CO2 Reactor 16/22mm
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External CO2 reactor for high efficiency CO2 dissolution by internal whirlpool waterflow, allowing 100% CO2 dissolution in aquarium water. Made of highest quality food grade materials.

  • mount outside aquarium tank, inline within outflow tubing of canister filter

  • fits tubing size 16/22mm ID/OD (inside diameter /outside diameter)
  • height: 15 inches (375mm)
  • diameter: 4.5 inches (116mm)
  • volume: 2.5 liters

Customer Reviews

20 reviews

  • 5

    Aquarium co2 reactor for planted tanks you cant pass up.

    Posted by Eli Montrose on 18th Sep 2021

    Great bargain for getting all your co2 100% saturated. It was easy to set up and my co2 is far more stable. You can view this data if you use a pH controller with an app interface. The difference I see is amazing. My graphs are much much more steady and not like a roller coaster. I had no idea. Im using reactors from here on out.

  • 5

    Quality aquarium co2 reactor.

    Posted by Mitchell Wheeler on 6th Sep 2021

    O looked at all the other reactors on the market and this one was the largest of all the ones I viewed, so I ordered it. It works exactly as GLA says and absolutely no need to burp out wasted co2. This thing saturates the co2 100%. You will be pleased 100%.

  • 5

    I love this co2 reactor.

    Posted by Lee Parsons on 3rd Sep 2021

    I waited until fall to order this reactor and could not be more pleased. Instructions were super easy, you dont really need them if you have half a working brain. My tank is now crystal clear and not a bottle of seltzer water lol.

  • 5

    Simple and effective.

    Posted by Mara Strouse on 27th Aug 2021

    I wanted to try a reactor with my new GLA co2 system so I figured now is hood a time as any. Prior to my reactor I used a misting diffuser that creates a very fine mist of co2, the plants loved it. The crazy part was my cat could see the bubbles and they attracted her to drink water from my aquarium. In came this reactor. Water is crystal clear right from the start. Real basic simple installation. Two hose barns and one co2 connecting point. Works great and loved the GLA support team.

  • 5

    Super co2 reactor!

    Posted by Barbera Diego on 26th Aug 2021

    I love this reactor, its so much larger than I anticipated but I feel thats to its working advantage. It saturates the co2 100%. However do know you still will want to clean the inside of the reactor after a few months. It grows the same bacteria that grows inside your filter. I did tno notice any reduction in performance when it was dirty, it was just unsightly. Otherwise a fantastic co2 reactor. Easy to follow instructions and the stickers were cool!

  • 5

    The best planted aquarium co2 reactor.

    Posted by Victor on 30th Jul 2021

    I switched out my previous reactor because it kept filling up with gas and you had to bleed co2 out all the time. I feel it was the design, perhaps to small. The GLA co2 reactor was very large in diameter compared to my old one. The whirlpool effect is really cool. 100% saturation and tuned just right.

  • 5

    Excellent aquarium co2 reactor.

    Posted by Jesse Armstrong on 25th Jul 2021

    I went from a DIY PVC reactor to this beast and what a difference. Its much larger than I thought it would be but its perfect. It comes with a check valve a small section of connecting tubing. You will need your own co2 tubing. Otherwise I love it, and the cool stickers that came with it!

  • 5

    Much larger than anticipated and works like a dream.

    Posted by Niles D. on 26th Jun 2021

    I was unsure what method of diffusion to use so I phones GLA via text and they helped me narrow things down to an inline co2 reactor. my tank is crystal clear now, no more foggy mist from the ceramic diffuser. I love the fact I dont have to clean it if I dont want to so my co2 levels are always on point 24/7 in my 90g.

  • 5

    Much better than my old co2 reactor.

    Posted by Jose Quinones on 9th Jun 2021

    I ordered this to replace an older reactor that could not be cleaned. The GLA co2 reactor is massive in diameter so you can clean it in seconds easily. During operation this thing functions flawlessly.

  • 5

    Very happy

    Posted by Reggie Williamson on 5th Jun 2021

    I love this reactor and it does exactly what a reactor should do. I learned a lot from GLA on how to properly dial in diffusion per the light levels in the tank. All while considering off gassing/surface agitation. Excellent co2 reactor!

  • 5

    Exactly what your looking for.

    Posted by Jeff Jansen on 29th Mar 2021

    Easy to set up and maximize your co2. Keeps the equipment out of your tank.

  • 5


    Posted by Rebecca A. on 9th Feb 2021

    I love this reactor. Very well made and could not be easier to install. I like that I dont have to clean my diffuser any longer, one less thing to do. It works just as intended. Totally saturates my co2 in seconds. The cool whirlpool motion has my cat mesmerized. The reactor is quite large, much larger than I anticipated only because I compare it to my previous reactor which appeared to be a DIY type reactor from another vendor. I reached out to GLA to have my reactor custom fit with two different hose barbs. If you need one for a 2217 filter they got you covered. Sweet co2 reactor no doubt.

  • 5

    Extremely happy

    Posted by Kyle Strom on 6th Feb 2021

    This reactor has been perfect since day one. Ive had it over a little over a year now. I can now see crystal clear water and have perfect co2 levels all day. It does take some getting use to if you new to using a reactor vs a co2 atomizer. One thing to note, reactors will use more co2 than an atomizer. This is to be expected because your aquariums water surface is an instant escape membrane for co2 to leave solution instantly. Whereas an atomizer keeps co2 mist in the tank for the most parts and the tiny bubble stick to the leaves and plants which they love. This is why atomizers use less co2 in most aquarium settings. I have the 16/22mm on my 75g tank and the 12/16 on a 55g and both use about the same amount of co2. cant wait to set up my new 125 with another 16/22:)

  • 5

    Perfect fit

    Posted by Glenn W. on 18th Jan 2021

    This reactor works perfect, and fits my cabinet really well because it stands on its own. It has my co2 saturated 100% and you barely have to do anything lol. It came with easy to follow Ikea style instructions, so if you have trouble its nobody fault but your own. Its a little expensive but the customer service and the whole experience was just super pleasant. The guys at GLA are stellar, and are always on tap to help. These guys are legit Co2 pro's. Not some posers like the rest of the stuff you see.

  • 5

    CO2 reactor

    Posted by Long on 19th Apr 2020

    I just set a new tank got an additional manifold block. I want to try out the co2 reactor. I read a lot about how efficient the co2 reactor is. I wanted to give it a try. I like the fact that the reactor is very big and stand on it's own. I added a small pump to the reactor. I ran the return hose line into the sump pump. The first few hours the water is swirling inside the reactor. So it makes a lot of noise. Once the reactor filled up. There is absolutely no noise. On the positive side to the reactor. You don't have to see the tiny bubbles floating all over the tank. You don't have to maintain it like you have to with the atomizer. I have been running it for a few weeks now.

  • 5

    Very Happy

    Posted by Jason Short on 12th Feb 2020

    Excellent build quality and easy to follow instructions. It takes all of 3 minutes to install. This co2 reactor is much larger than any other reactor I have ever seen or used. Perhaps thats why it works so well. The way the whirlpool motion happens inside the co2 reactor is quite cool. This is what gets the co2 100% saturated. I run a fairly high bubble rate on my 180g tank and this reactor has no issue handling this tank. I will be buying another one as soon as my tank arrives next week. Very happy!

  • 5

    Outstanding co2 reactor

    Posted by Terry Williams on 18th Jan 2020

    I purchased this reactor to go with my Pro-DS co2 regulator. I really like this reactor because it keeps co2 stable in my 180g tank. My previous co2 reactor was simply to small to handle the co2 going into it. Simple installation and very cool whirlpool effect it creates inside. It also looks cool unlike the rest you will see on the interwebs:) Very high quality unit.

  • 5

    Excellent co2 reactor.

    Posted by Eva Simons on 15th Jan 2020

    This is my first time using a co2 reactor so I dont have any other reactor to compare it to. However I was using a ceramic style co2 diffuser and I was not fond of the constant cleaning or the bubbles flying all around. This reactor totally saturates the co2 prior to going into your aquarium. I dont see not a single bubble exiting the reactor. I like the cool whirlpool effect it creates and Im guessing this motion is what saturates the water with co2. Installation is really easy and the instruction diagram was great, although not really needed because the its pretty straight forward. Cant wait to see my plants take off now! They are already pearling after only 1hr of using the co2 reactor. Gotta love that!

  • 5


    Posted by Shane Mallery on 15th Jan 2020

    This is only my second reactor after having used a DIY serges co2 reactor for a few years. After speaking with GLA about diffusion in a planted tank I quickly realized my approach to diffusing co2 with my reactor was all wrong, or just way off. The first thing you will notice with this co2 reactor is its huge diameter. Its big like a small canister filter. One point that GLA drove home to me was that if your using a co2 reactor and you get a big co2 gas bubble inside your reactor, its a clear sing your doing things wrong. With balanced co2 diffusion you should have minimal co2 build up. If you find a huge gurgling gas bubble inside your reactor your wasting co2 and your install is not set up correctly. Proper flow through the reactor coupled with well balanced surface agitation should leave you with a nice even co2 flow rate that relates well to your filter flow rate. A reactor should not have a bleed off valve built in, just think about that and let that sink in. Bleed of co2 you inject? lol No thanks. Thank you GLA for providing the US a fantastic working co2 reactor. This reactor will come with tubing lock nuts and or lock rings depending on your tubing dimensions. You get one set for really thick tubing(threaded lock rings) and a set of tubing locking rings for basic hose barb connection where you would not use the threaded tubing lock rings and simply use the clamps they provide. Install only too me 5 minutes, the way the co2 flows inside the reactor mimics a whirlpool so its pretty cool to see the co2 get churned up. So much better than my previous co2 reactor!

  • 5

    Perfect in every way.

    Posted by Felix Guzman on 12th Jan 2020

    This is my third co2 reactor being used on my 220g tank. The first two were nilocg reactors. After receiving this reactor Im so happy to have those home made reactors off my tank. The GLA reactor does not require ball valves to get proper saturation. Therefor you have no loss in filter flow rate. The cool thing about this reactor is how it works. It creates a neat whirlpool effect inside the reactor. No media required and no ridiculous ball valve. This reactor works extremely well and is very well built. It has some girth to it so be prepared. It has a massive 4.5" diameter so make sure you have the space under your tank. This is not your run of the mill reactor, its built purposeful for aquascaping. Your simply not going to find a better reactor on the market, no way in hell! So happy with my GLA co2 reactor:)

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