CO2 Glass Aquarium Supply Accessories, CO2 Diffuser CO2 Drop Checker CO2 Bubble Counter Check Valve for Aquarium Planted Tank (Check Valve)

Works great with an in-line C02 system! But will not work with an air pump, it’s too tightly sprung to open with for a air bubble pump.

Doesn’t work, if there’s no co2 pressure in the line then water goes right through which defeats its purpose

Works with my pressurized CO² generator & diffuser. I prefer this type with the barbs, as it's less likely pressure build up, when clearing water from the tubing, blows the line off. Plus the stainless looks really cool with my black tubing. Gonna get more for my air bubbler too, because the line sometimes tend to disconnect there. It probably happens more often with timer setups. When the CO² and air pump are off water backs up to the check valve. When they're turned back on it initially takes more pressure to clear the lines of water than it would if they were constantly running. I try to put the check valve close to the water level so there's less water to clear out when the pump & gas are turned on. Just something to keep in mind if you have or are considering alternating your CO² & air pump with a timer or even manually.

Pretty tough piece. But... it may require a lot more pressure than you would imagine to let it open. I may try another one way and evaluate if this tiny piece is the whole cause of the headache or not next week. Basically you cannot blow with your mouth from feed end, unless you put compressed gas through it. So it may stay or get repurposed at somewhere soon. Add: return of product was the decision. basically its cracking (unseating/opening) pressure was too high for my regulator with 5lb tank, so they are going back to wherever they came from. Cracking pressure on those valves should be available on description instead of "High pressure" i guess 1atm is 14psi so 5psi is a low pressure but yea would be nicer if I knew actual pressure prior. It would work if your feed line is 10~15psi or so, if regulator is set around 5 and using for nano tank it may not work.

Purchased both the spiral diffuser and a few check valves and all work as intended. I hooked everything up to test yesterday. The micro bubbles out of the diffuser were as good as anything else I've ever used. I connected it for about 15 minutes and had a fine Co2 mist swirling around immediately. Soaking in water right now and after about 10 hours, it's about halfway full of water. Check valves worked the right way and stopped the Co2 when I flipped them around. Would definitely buy again.

Check valve fit right in line and appears well made, body all metal with good barbs on it. Will update if anything changes. Using for co2 injection in aquarium upstream og the bubble counter.

Used for about 2 weeks and some how does not work even when blowing air through it from either end

At first I thought it was not working properly. I tried blowing through this and it seemed not to be working (and yes I was blowing in the correct direction). Then I installed a cheap check valve in my CO2 system and all it did was leak because of the pressure. So I went ahead and tried this check valve and it works perfectly with no leaks. I guess you need to have it under more pressure than just trying to blow through it.