Description
GLA Onyx CO₂ Atomizer Diffuser (Ultra-Large)
Ultra-Large Black Ceramic CO₂ Diffusion for High-Demand Nature Aquariums
The GLA Onyx CO₂ Atomizer Diffuser (Ultra-Large) is a purpose-built, ultra-large in-tank CO₂ diffuser designed for planted aquariums where conventional atomizers may be undersized. Featuring one of the largest diffusion surfaces currently available for nature aquariums, the Onyx provides efficient CO₂ dissolution with microfine, uniform bubble output in a clean, minimalist form.
At the core of the Onyx is a thick, high-density black ceramic disc with an approximate 40 mm (1.5 in) diameter, paired with a compact 85 mm low-profile body. The oversized ceramic surface allows for higher gas throughput while maintaining fine, consistent bubble formation, making it well suited for larger aquascapes, high-light systems, and higher CO₂ demand.
Recommended Aquarium Size
Due to its large ceramic surface area, the Onyx is best suited for medium to large planted aquariums, generally 40 gallons and larger. Smaller aquariums may still use this diffuser; however, users should be aware that the ceramic disc is physically larger than standard diffusers and may be visually prominent in compact tanks.
Why Black Ceramic?
- Reduced visual distraction compared to traditional white ceramic diffusers
- Less apparent biofilm and algae visibility over time
- Blends naturally into dark substrates, hardscape, and shadowed areas
- Maintains a clean, professional appearance between maintenance intervals
While no ceramic diffuser is completely algae-proof, darker ceramics tend to show buildup less readily, helping the diffuser retain a cleaner appearance over time.
Precision Construction & Materials
- Ultra-thick black ceramic disc for high diffusion efficiency
- Microfine, uniform bubble output for effective CO₂ absorption
- Crystal-clear acrylic body that is durable and impact-resistant
- Acrylic construction is less fragile than glass while maintaining clarity
- Low-profile, minimalist design for in-tank placement
- Smooth, tapered tubing inlet for easy and secure tubing installation
- Designed for in-tank CO₂ atomization with high dissolution rates
The acrylic body provides long-term durability with a clean, unobtrusive appearance inside the aquarium.
Installation & Use
- Includes two clear suction cups for secure mounting
- Compatible with standard flexible CO₂ tubing
- Intended for use with pressurized CO₂ systems
Important:
For best performance, the ceramic diffuser should be soaked in water for at least 24 hours prior to first use. This allows the ceramic pores to fully saturate and helps ensure consistent bubble size and diffusion from startup.
Specifications
- Ceramic Diameter: approx. 40 mm (1.5 in)
- Total Height: approx. 85 mm
- Material: Black ceramic diffuser disc with clear acrylic body
- Mounting: In-tank, suction cup mounted
- Included: 2 suction cups
Application
The Onyx CO₂ Atomizer Diffuser (Ultra-Large) is designed for aquarists seeking a large-format, efficient in-tank diffuser with a clean appearance and durable construction. Its oversized ceramic surface makes it an excellent choice for planted aquariums with higher CO₂ demand, while the black ceramic and minimalist design integrate naturally into modern nature aquascapes.
Customer Reviews
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It sure is pretty!
This is a very nice diffuser that works very well. Using this in my 75g and provides ample co2. Make sure to soak for 24hrs before using. Very very good looking diffuser. Just wish all my other gear looked equally as pretty lol
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Will be switching all my in-tank diffusers to this.
I only bought one just to test drive on a 90g and it’s very nice. Works fantastic and really love the sleek black ceramic vs my old bright red ceramic. Diffuses well and just looks very professional.
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This thing is awesome!
By far the nicest diffuser I’ve used. I got this for my ADA 120p and it looks so much prettier than the glass ADA diffuser, very slick design and the black ceramic looks cool. Atomization is very nice, on par with the red type only much larger in size so it handles high flow rates much better. GLA knocked it out once again, can’t wait to see what next from GLA.
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It’s big, so be sure to review its size.
I ordered two of these for my 6 foot aquarium and they are perfect. The dimensions are listed so be sure to review them. I was thinking of using one in my 20g but it would be quite big in the tank. GLA told me this diffuser is designed for higher co2 bubble rates typically associated with large tanks, not designed for low flow smaller tanks. Although I suspect you can still use it. It’s a beautiful diffuser that’s for sure. Always like what GLA does for the co2 planted tank community. Looking forward to my next purchase.
