Description
GLA PRO-CO2 Reactor 5L – Maximum CO2 Saturation for Nature Aquariums / Planted Tanks
Our GLA PRO-CO2 Reactor is engineered for unmatched CO2 dissolution, delivering maximum efficiency with zero waste. Designed for serious aquascapers, this reactor ensures stable, high-level CO2 saturation, optimizing plant health and growth in high-tech nature aquariums.
- 5L High-Capacity Chamber – Handles high-flow filtration while maintaining consistent CO2 saturation.
- Precision-Designed in the USA – Built from professional-grade acrylic (19" tall × 6" diameter) for durability and performance.
- Whirlpool Diffusion System – Creates a high-flow vortex, ensuring complete CO2 absorption before water returns to the aquarium.
- Universal Fit – Compatible with 12/16mm, 16/22mm, and 20/25mm tubing, seamlessly integrating with canister filters and external pumps.
Installation & Functionality
1️⃣ Connect inline with your canister filter’s output.
2️⃣ Attach CO2 tubing using the easy Speedfit connection—a secure, tool-free fitting with a built-in on/off valve for precise CO2 adjustment.
3️⃣ Let the vortex effect optimize CO2 dissolution, ensuring full saturation before water returns to the tank.
4️⃣ Fine-tune CO2 levels to meet the demands of your planted aquarium.
Built for aquascapers who demand professional-grade performance, the GLA CO2 Reactor delivers precise CO2 control, unmatched efficiency, and superior plant health.
Customer Reviews
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GLA has the best co2 equipment no exception here.
I have the first gen version of this reactor in steel and very pleased with it. I waited a while for my second tank to get all the bits in line and this was the final piece. After two days of dialing in my co2 this thing is incredible. My water is crystal clear and plants are pearling like mad. I get more pearling plants with this reactor than I did with my inline diffuser. Solid build quality typical of GLA.
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Loving this reactor so far.
Ditched my inline diffuser for this and the results are incredible. My atomizer never made my plants pearl nearly as much. Didn’t take long to get dialed in thanks to the support from GLA. Their tech support is amazing and very helpful. If you buy this and never used a co2 reactor before, reach out to these guys and save yourself the time of knowing how to properly use a reactor. You won’t regret it.
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This is what a co2 reactor should be.
Retired my previous reactor to give this a whirl and man is it a beast. I have it hooked up to my Eheim Pro 3E and it’s a beast. My co2 is totally saturated and by late noon my plants are pearling like crazy. This thing is awesome!
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What an absolute beast of a co2 reactor wow!
I was pleasantly surprised when I opened the box. This is larger than my co2 system. This is an absolute unit! I use Eheim 2262 to power this monster. I spent 3 days fine tuning the reactor which prepare yourself it will take a few days. GLA sided me in getting me dialed in and I learned so much. There expertise and vast knowledge paid off. David was all hands on deck getting my 150g tank dialed in to perfection. I have 100% saturation, no huge gas bubble in the reactor. Drop checker almost a lime green at 2.5 bubbles per second, possibly 2 per second. 3 days of tuning and I’m on day 9 and haven’t touched anything in my co2 system. I find myself tending to the plants more than anything and no more diffuser cleanings. Happy camper here!
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Best co2 reactor ever built.
The reactor works extremely well with my Fluval FX. 100% saturation of all the co2 I inject is all I ask for. Only took me about 2-3 days to dial in to perfection. A+ co2 reactor GLA!
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Our shop 100% approves of these baby’s!
Our shop recently took in a shipment of GLA goods and onboard were a bunch of these reactors for a new set of display tanks. Most of not all our techs are not huge fans of atomized co2 in the tanks as they tend to feel distracting. We’ve already set up several here and in client installations and can confidently say these work extremely well. We use only XL canister filters from Ehiem and Aquaelle. These filters are huge and push big flow which mates well with this reactor. Crystal clear water and an amazing amount of pearling from the plants, including in our plant display tanks. GLA does a great job at bringing quality to aquascaping.
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This is the pinnacle of what a co2 reactor should be.
3rd times the charm as the old saying goes. I’ve tried GLA’s competitors reactors and without fail they all need burping of co2 gas. I have a lot of money invested in co2 reactors and I feel I have the concept down, or you’d think by now I do. I’ve had this reactor installed almost 3 weeks, I had it dialed in by day 3 and haven’t touched my setting since. First off, this thing is huge, 5L is a big ol hunker of a reactor. The 45* elbow is very nice becouse I see zero loss of flow. But here’s where it gets interesting as I’m not sure if people understand what’s happening in the tank and it’s something I noticed on the 3rd day. You’re going to see your plants start pearling, and I mean a lot of pearling. So much that I noticed my reactor was sucking in loads of oxygen produced by plants. All that air produced by plants was going into my filter, causing nous and also injecting air into the reactor both. Although I feel most stayed inside the filter. With GLA’s tech support I simply repositioned my filter inlet a few inches away as to not be so close to the plant bed. Huge difference the next day! No kore noise from my filter having air in it and nothing going into the reactor. Plants pearling like absolute crazy is a good thing and tells me this reactor is just incredible. GLA always putting out the co2 gold!
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Much improved from an inline diffuser.
I switched from an inline because I hated the 7-Up look in my tank. I had no idea how foggy my tank was until I had co2 for a whole day. One week later and this puppy arrived and wow! My plants are pearling like never before and the view is crystal clear. I love it!
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I would buy this if you want the best co2 reactor.
Took the plunge last week and its been one awesome co2 reactor. Took me about 2 days to dial in and my plants are pearling like mad! This is a big reactor so prepare yourself. Worth every penny spent.
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One amazing co2 reactor, high quality.
Very pleased with this co2 reactor. Extremely large at 5L in volume. Minimal to no pocket of co2 with my co2 flow rate and pump, Im blown away because using other brand reactors leave a massive pocket of gas, but not this one. I see high flow exiting the reactor into the tank which pleases me because I know the reactor is not impeding my pump flow. Kudos to GLA design on this it works extremely well.
