I bought one initially, and it worked amicably. I only bought a second one because I didnt know how to setup my bubble counter at the time - but I went with it because not only was it affordable, its also quality!

Works perfectly with my micro co2 set up. Have not had any issue's with it.

This is exactly what my Co2 needed. its well made and the co2 tubing fits nice and tight !

I am using this stainless steel check valve as a one-way valve in my co2 system on my planted aquarium. The build quality and fit and finish is excellent (makes fitting airline tubing easier), and the directional arrow is very conspicuous and easy to follow.

Note that this valve will not work in non-pressurized systems. This means that an air pump will not be strong enough to pass air through this valve. It is designed for pressurized systems like co2 canisters.

I ordered this along with the new regulator from Aquarium Co-op and it works just fine. Bubbles are appearing in my diffuser and no water is leaking when the regulator turns off every night. The check valve is nearly the same width as the airline tubing, so it looks really nice and streamlined. Plus the arrow makes it easy to tell which way to install it. I wish regular plastic check valves had the same arrow.

If you are running CO2 for your plants and invested in an upper end dual stage CO2 regulator you should do 2 things: 1. Use designated CO2 tubing to prevent leaking, and 2. Use a stainless backflow valve like this one, as the plastic valves designed for air made of plastic won't protect your equipment from getting ruined by backflow.

Easy install, seems high quality and flow is clearly marked. No complaints

The valve is well constructed and sturdy. Easy to attach the CO2 lines to thanks to the ‘ribbed’ collars. Works seamlessly, and prevents aquarium water from flowing into CO2 lines.

I have a CO2 system that the plastic check valve leaked. I purchased this one and never looked back.

This is by far the best purchase I’ve made for my CO2 system! It works flawlessly and has never let me down. I’ll definitely be buying another one for my other tanks in the future.

Was tired of going through plastic check valves that would fail after a few weeks and allow water to backflow when the pressure inevitably dropped in my DIY CO2 setup, these metal valves work great and are were a necessary upgrade worth every penny.

Works as intended

Maybe a defective item but wouldn't work. Kept blowing the co2 supply line off no mater what direction the valve was installed.

Excellent product. Will definitely buy again as needed.

I like the arrow that shows the direction of placement for the CO2 line. Easy to place. It works.

Working great!

Much better than using the cheap plastic ones when running CO2. Water hasn’t gotten past yet. Going to be buying more for the rest of my tanks.

Works just as you’d expect.

The valve works great! It connects to the tubing without any issues.

Always pleased with my Aquarium Co-op purchases. Check valve was made of quality materials and great price. Just what I needed to complete my CO2 setup.

I got this for my small CO2 system as I was having trouble with back pressure building up overnight and then delaying the CO2 start time. Put this in line and that problem vanished. Highly recommend.

Never have I laid eyes upon a more perfect check valve for CO2 lines. Be careful with these bad boys. They’re so awesome, you might throw up. I am in no way leaving this review for the 5% discount code.

Love, John

I am not a fan of things that leak. It’s never good. The stainless steel check valve from Aquarium Co-Op solved my disappearing CO2 issue. Replacing the plastic valve I had with this steel one immediately produced results. No more disappearing bubbles for this aquarium.

I purchased this product a second time after seeing the quality of the product on the first purchase. Its fit perfect with my standard airline setup and CO2 specific airline with no leaks. I wish you could get regular check valves of this same quality.

Much better than the plastic ones for sure! Gives piece of mind you won’t drain the tank into the living room.

Recently purchased this check valve, does not flow in either direction. Might just be a dud. Will have to do more research on other products.

exactly what I expected, thank you!

CO2 Stainless Steel Check Valve

Did not flow in either direction. I believe mine to be a dud and probably not the norm but I was prompted to review it.