Description
GLA GRO Planted Aquarium CO2 Regulator
Precise CO2 control in a compact, easy-to-use design.
The GLA GRO Aquarium CO2 Regulator combines piston-type pressure regulation, precise CO2 adjustment, and automatic operation in a compact design. Its integrated components make it easy to control and monitor CO2 delivery without requiring a large regulator assembly.
GRO can supply a single planted aquarium or multiple aquariums with the optional GRO CO2 Splitter. Each regulator is individually inspected, pressure tested, and leak checked in the USA before shipment.
At a Glance
- Pressure Regulation: Precision piston-type mechanism
- Cylinder Connection: CGA-320 standard USA CO2 cylinders
- CO2 Adjustment: Precision needle valve
- Automation: Integrated electric solenoid
- Monitoring: Working-pressure gauge and bubble counter
- Expansion: Optional GRO CO2 splitter for multiple aquariums
Best For
- Single planted aquariums of various sizes
- Compact installations where equipment space is limited
- Aquarists who want precise CO2 adjustment and automatic timer control
- Existing CO2 setups using compatible CGA-320 cylinders
- Multiple aquariums with optional GRO splitter expansion
Why Choose the GLA GRO?
GRO combines the essential components for precise, automated CO2 delivery in one compact regulator. Here's what its features do for your aquarium setup.
- Piston-Type Pressure Regulation: Reduces cylinder pressure to a stable, adjustable working pressure for consistent CO2 delivery.
- Precise CO2 Adjustment: The needle valve allows fine control of CO2 flow and can be rotated 360° for convenient positioning.
- Automatic CO2 Control: The integrated solenoid lets you turn CO2 injection on and off automatically using a timer or compatible controller.
- Easy Monitoring: The working-pressure gauge displays regulator output pressure, while the bubble counter provides a visual reference for adjusting CO2 flow.
- Integrated Protection: A pressure relief valve provides additional protection, while the bubble counter check valve helps prevent aquarium water backflow. Micron filtration helps protect internal regulator components.
- Durable Construction: An aluminum regulator body, precision metal-on-metal valve seat, and quality pneumatic components are designed for long-term use.
- USA Inspection & Testing: Every GRO regulator is individually inspected, pressure tested, and leak checked in the USA before shipment.
What's Included
- GLA GRO CO2 Regulator
- Integrated electric solenoid
- Integrated working-pressure gauge
- Precision adjustable needle valve
- Integrated bubble counter with check valve
- GLA OEM CO2 tank seal
What You'll Need Separately: A compatible refillable CO2 cylinder, CO2-resistant tubing, and a diffuser, inline atomizer, or reactor are required to complete your CO2 installation. These items are sold separately.
Need a cylinder too? Explore our GLA GRO Complete CO2 System, which includes the GRO regulator, a refillable aluminum CO2 cylinder, and selected installation components.
Optional Multi-Aquarium Expansion
The optional GLA GRO CO2 Splitter allows one GRO regulator and CO2 cylinder to supply multiple planted aquariums.
Each splitter outlet has its own precision needle valve, so you can adjust the CO2 flow independently for each aquarium without replacing your existing regulator.
Technical Specifications
- Model: GLA GRO Aquarium CO2 Regulator
- Pressure Regulation: Piston-type mechanism
- Cylinder Connection: CGA-320, standard USA CO2 cylinders
- Adjustable Working Pressure: 0–70 PSI
- Pressure Monitoring: Integrated working-pressure gauge
- Needle Valve: Precision, 360° adjustable
- Automation: Integrated electric solenoid
- Bubble Counter: Integrated, with check valve
- Pressure Relief: Integrated pressure relief valve
- Regulator Body: Aluminum construction
- Valve Seat: Laser-precision metal-on-metal
- Filtration: Multi-stage micron filtration at inlet and outlet
- Multi-Aquarium Expansion: Optional GLA GRO CO2 Splitter
- Quality Control: Individually inspected, pressure tested, and leak checked in the USA
The GLA Difference
20 Years of CO2 Expertise. A Commitment That Goes Beyond the Equipment.
For 20 years, Green Leaf Aquariums has specialized in CO2 equipment for planted aquariums. Throughout that time, we've remained committed to advancing the quality, precision, and reliability of aquarium CO2 regulation. Our experience, long-standing manufacturing partnerships, and close relationships with our customers have helped shape the equipment we offer today.
We don't believe in standing still. We work closely with our manufacturing partners to continually refine our products, incorporate real-world customer feedback, and introduce meaningful improvements. From precise piston-type regulation to advanced dual-stage designs and modular expansion, GLA has consistently worked to raise the standard for aquarium CO2 equipment through thoughtful engineering and innovation.
Every GLA CO2 regulator is individually inspected, pressure tested, and leak checked in the USA before shipment. We take quality control seriously because we understand the importance of dependable CO2 delivery and the trust our customers place in our equipment.
But what truly sets GLA apart is the company behind the products. We're a small business with a personal commitment to the people we serve. We take pride in helping customers select the right equipment, answering technical questions, providing installation assistance, and offering knowledgeable support long after the purchase. We're invested in our customers' success, and we genuinely care about their experience.
That commitment is backed by our Limited Lifetime Warranty on GLA CO2 regulators and systems for the original purchaser, covering qualifying defects under our warranty terms.
When you choose GLA, you're investing in more than precision-engineered CO2 equipment. You're choosing two decades of specialized experience, continuous product development, careful quality control, and a business that stands behind what it sells.
Twenty years of experience. A continuing commitment to innovation. A company that stands behind you.
Frequently Asked Questions
What does piston-type pressure regulation mean?
Piston-type refers to the internal mechanism that regulates CO2 pressure. GRO reduces cylinder pressure to a controlled, adjustable working pressure for aquarium use.
What size aquarium can I use GRO with?
GRO is suitable for a wide range of planted aquarium sizes. CO2 requirements depend on lighting, plant demand, circulation, and diffusion equipment rather than aquarium volume alone.
Can GRO supply multiple aquariums?
Yes. The optional GRO CO2 Splitter allows one regulator to supply multiple aquariums, with independent CO2 flow adjustment for each outlet.
Can I use GRO with an inline atomizer or CO2 reactor?
Yes. GRO supports common planted aquarium CO2 diffusion methods, including in-tank ceramic diffusers, external inline atomizers, and compatible reactor systems.
Does GRO include a CO2 cylinder?
No. This listing includes the GRO regulator and its integrated components, plus the GLA OEM CO2 tank seal. The cylinder, CO2-resistant tubing, and diffusion equipment are sold separately.
Which CO2 cylinders are compatible?
This GRO model uses the CGA-320 connection for compatible refillable CO2 cylinders commonly used in the USA.
Pre-Sales & Installation Support
GLA provides expert pre-sales assistance, equipment compatibility guidance, and installation support by email and text. Whether you're selecting accessories or setting up your CO2 regulator, we're here to help.
Support & Warranty
GLA Warranty: GLA CO2 regulators include a Limited Lifetime Warranty on qualifying mechanical manufacturing defects and a 2-Year Limited Warranty on qualifying electrical manufacturing defects. Coverage applies to the original purchaser and is non-transferable. For complete systems, regulator warranty coverage does not automatically extend to cylinders, tubing, or other accessories.
Service & Returns: GLA prioritizes repair whenever practical. CO2 regulators and systems are not eligible for voluntary returns. Warranty claims require GLA evaluation and authorization before equipment is returned for service.
For complete coverage, exclusions, service procedures, and domestic and international warranty terms, review our Shipping, Returns & Warranty Policy.
Customer Reviews
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GLA quality is impressive.
This is a high quality built regulator. Impressive weight to this regulator but more so the effortless tubing of bubble rate. It’s rock steady everyday.
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Heavy duty co2 regulator.
I was replacing my Fzone regulator that was giving me inconsistency in bubble rate dramatically. To the point the end knob of the needle valve came right out. The valve came apart like some catastrophic failure for no reason. I emailed GLA first so they ensure this won’t happen. Not only did it arrive quickly but upon installation I could feel the difference. Also, they provide a tool to completely rebuild the needle valve. It’s serviceable! Unbelievable if you ask me. The whole regulator is serviceable. The regulator itself is twice the weight of an Fzone regulator, this tells me it’s made of serious materials and it shows. You’ll see for yourself the instant you pull it out of the box. High quality and precision flow I can rely on is all I asked for and GLA delivered 100%. Thank you GLA for great product and remarkable service. Best, Brant
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There’s no better co2 regulator for this price.
I spent months doing my research, even went to Aquashella trade show and saw this in action. This is so much better than Fzone or Co2art. The weight of this thing compared to those is immense, this thing is beefy and it’s been rock steady every day. I like the valve assembly especially because you have such fine control of the bubble rate. The warranty is also incredible. GLA is worth every penny.
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Very well crafted co2 regulator.
Replaced my Co2art regulator with this GLA compact unit. First off out of the box, it’s very heavy, twice the weight of Co2Art. Seems to have some very heavy duty construction that feels good in the hands. Like a nice watch. Secondly, it flows with precision. I had it installed in minutes and supplying my 29g shallow tank. In my opinion this is a great buy from GLA. Good quality and service from the GLA staff.
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Great regulator
Just came in today and feels well built with amazing quality. Would definitely buy again or recommend
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The best aquarium co2 regulators.
GLA makes the best co2 regulators hands over fist compared to Fzone. I threw that stupid thing into my trash bin. Sad, but glad I own GLA co2 regulator now, huge improvement in quality.
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Happy to own a GLA co2 regulator!
I’ve wanted a GLA regulator for years and finally pulled the plug. This regulator definitely out performs my cheap regulator. You don’t realize how nice a regulator can be until you have one of these beauties in your hands. Pleased would be an understatement.
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High quality and precision co2 delivery.
After several emails I went with the Gro, happy I did because I was on a budget and wanted the known service and warranty GLA is known for. It’s been a pleasant experience and today I’m on my second cylinder refill. Also added new fish today as my scape is evolving into a jungle. It was a very easy regulator to install even after forgetting how to on my refill. Luckily GLA has videos to follow which made it painless. Buy one cry once they say, GLA is a solid company to shop with.
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Five star quality and support!
Love GLA products but this Gro regulator is a warm welcome in my house. No more janky lightweight co2 regulator I used from Amazon. This is heavy duty and flows with precision. Buy with confidence from GLA, cant go wrong here.
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My aquascape thanks you!
Love this regulator, it’s my first and I’m a proud momma. My plants are growing extremely well. These guys ship and pack like nothing else. Love the customer service people, so helpful and always supportive with that text app they have.
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We love this co2 regulator.
We got this with GLA’s 2.5lb co2 cylinder and we love it. It’s a high quality piece of equipment and grows our plants like a champ, love it!
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Very nice!
Extremely happy, it was shipped fast! Moreover installation was painless. It’s a very nicely crafted piece of equipment. Saw these at a trade show and is why I bought this. It flows like a fine wine ?
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Heavy duty way better than my UNS regulator.
This regulator is so much better than the UNS regulator I have. First thing I noticed is the shear heaviness of the regulator. The most important part in my opinion is the connecting nut. Geez, you’d think UNS would use a substantial nut, nut Noooo! They use stupid aluminum for a high pressure connecting nut. That thing not only was destroyed on the outside but after a couple refills the threads inside started inverting. Yes, they started to bend into themselves because they are just soft. GLA Gro uses a nickel plated heavy duty nut that’s just solid as ever. Feels really good, but let’s move further. This needle valve is much nicer, better control that’s not all erratic with mild adjustments, it’s very precise. GLA is a level of their own and explains their notoriety. Go with GLA and not the replicas who try to follow what they do.
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Love it!
Super happy, shipped very quickly and the customer service was fantastic. My tank is growing extremely well and look forward to buying more plants for it. Thank you GLA and John who helped us!
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GLA makes the best co2 regulators.
This is my 2nd Gro regulator. My first was purchased in 2007, iI still use it in my living room aquascape. I got this one for my basement tank. These things are built like tanks. What I truly love about them is the needle valves easy tune ability. I don’t know what the correct verbiage is for this but in essence it’s super smooth at adjusting the co2 bubble rate, and it stays put from start to finish. One time my cat knocked over the whole system. The regulator didn’t flinch one bit, nothing broken like nothing happened at all. Impressive quality so you can buy with confidence. Fantastic customer service reps every time.
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We love it!
We love this regulator, such a vast improvement to the shitty Fzone regulator. Very heavy duty and only a few minutes to install. I did forget to order the GLA tubing but I ordered that and all was good!
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Much nicer than their competitors I wish I came sooner to buy GLA.
Don’t settle for garbage because that’s what Fzone and Co2art are. My husband was absolutely livid spending money on them. We even argued about it because people talked up those brands. We started with the cheap one from fzone and my god you don’t even have to be experienced in co2 to know right away what poop the quality is. After only 2 months of fiddling we spent even more for Co2art. Wtf do people like about these becouse they are both the same garbage. GLA should figure a way for customers to post photos becouse I shit you not those brands are ripping people off. It’s like they are made of recycled Bud Light cans. They leaked and the bubble counters break off but more noticeable was the lack of fine tuning to the co2 bubble rate. They probably would have been better made out of wood ?. No kidding! Fast forward to now and geez GLA was an instant relief. Very high quality build with substantial weight. You feel the quality right away. Very very nice control of flow and rock steady. We are on our second cylinder refill and could not be more pleased. The ph controller we use from Apex shows us the level of stability via the graphs and GLA has it dialed in! Buy with confidence and go with GLA co2. Save your money!
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CO2 Regulator
I'll start by saying I owned a Milwaukee regulator which was well over 20 years old and gave me me problems from the very beginning. In my last move the glass bubble counter broke so I had the option of either replacing the bubble counter or going for something new. I opted for the latter and I'm very happy I did. This unit feels beefy and accurate. I made sure I snugged it up well and set it. That's it! It's doing its job for almost two months now and I've had zero issues. Highly recommended.
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The best!
My 2nd Gro regulator for my basement system. I love these compact Gro regulators, stable like a dual stage regulator, more compact and the flow coefficient of the valve body is like no other. GLA always has the best valves.
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So happy now that my tank is glowing.
Took the leap into co2 after days of research. I always came back to GLA. The service and this regulator are worth every penny. We love it1
