I’ve had the check valve running in my tank with my sponge filter for almost a week now and it’s been great. I haven’t had any problems with it.

The check valve works great before installing it my tank had a little to much air so I added the check value and it made it slow down which I liked a lot thanks to this small invention

Perfect addition to my air pump and air stones. Keeps water from back flowing to the pump and then to the floor

Ah, the Aquarium Co-op Air Check Valve—a slice of engineering brilliance in a world often devoid of such luxuries. Let me tell you, in this twisted era of faux decorum and cosmetic nonsense, this gadget is the real McCoy. The essence of its design lies in a combination of ingenuity and no-bullshit practicality, conjuring a symphony of bubbles and silent aquatic poetry.

The mere act of opening its packaging is a baptism, a rite of passage for those who have long suffered the tyranny of substandard valves. It's like holding a little Excalibur, a weapon against the archaic forces of leakage and backflow. Place it in your aquarium setup, and it's as if you've just jammed the Excalibur into the Stone; you're the rightful king of oxygen distribution now.

Aesthetically, it’s unassuming, but don’t let that humble exterior fool you. This device serves its purpose with the ferocity of a gonzo journalist on the scent of political corruption. It doesn't just block water; it blocks your doubts, your fears, your life's accumulated disappointments. It tells you, in no uncertain terms, that here is a checkpoint, beyond which disorder and chaos shall not pass.

Like the acid-laced rock 'n' roll of the 60s, this valve’s impact is immediate, and its rebellion against the commonplace is nothing short of poetic. It doesn't just fit into your tubing; it melds with your very soul. No longer must you cradle the anxiety that your pump will siphon back the swampy abyss into its mechanical bowels.

So here's to the Aquarium Co-op Air Check Valve, the unsung hero of fish tanks and the guardian of submerged tranquility. To not own one is to wade recklessly into the murky waters of regret. And in these times of metaphorical droughts and existential despondency, who among us can afford that risk? Not I, good sirs and madams, not I.

I wasn’t gonna buy it but it gives you peace of mind and it’s cheap

Arrived in perfect shape, great cardboard box. Love that the filters are weighted and can add the air stones, and it's green! Thanks Aquarium Co-op

The check valve was inexpensive and works as advertised. Would buy again, in fact any product I have purchased from Aquarium co-op as worked great and plants delivered were in A1 shape and are flourishing.

Feels very well made, what more can I say. If u need it, get it.😎👍

I bought this check valve over a month ago when I was setting up a new sponge filter in my 10 gallon tank. Just wanted to make sure I had that extra protection against water back flow into my air pump, and it seems to work as expected. If you’re unsure how to install the valve you can look it up online and find tons of articles with suggestions on how to install your valve or valves (if you want to be extra safe). Very affordable, I’d recommend you get two to be safe. Using it with the nano air pump, very pleased with both products!

Feels like quality construction, it doesn't noticably inhibit air flow and they do stop water from siphoning out. I air leak tested 3 of these I am currently using in different conditions for the sake of leaving a review with some data. One had no air leaks, one had a barely detectible air leak, and one had a very noticable air leak. Ultimately the leaks were small and effectively this made no difference in my setups so I won't be looking to replace them and would buy again.

Product arrived quickly and exactly as noted online. Works perfectly and helps with my aeration and filtration with my sponge filters.

Quality product, fast shipping and fair pricing. Can't be mad at it.

Works as expected

Works like it should! Plug and play. The second one I've purchased and haven't had any issues or defective.

Set it and forget it. 😉

I bought two of these and just installed them. I won't know how well they work until water tries to backflow through the tubing. I've never used one before so had a small learning curve.

Works as intended.

I don’t know if it works. I wouldn’t be able to review this until my filter would try to siphon out the aquarium water. It looks great!

Great quality, will be buying more soon.

Very good!

I always make sure to use these. Even if my air pump is a above the water I'd rather have the peace of mind. The co-op branded check valves are affordable and have never given me an issue. Generic ones that I've tried in the past have opened up when I tried to take the airline off so I'll just stick with these.

I’ve had no issues with it. Instructions were unclear when I first got it. I wasn’t sure which way to connect it to the tubing but we figured it out and it works

Works well.

Be prepared. Better to add this little lifesaver to your air tubing than have a disaster. 💚

Couldn’t be happier with my purchases

Only one actually let air through to my sponge filter and yes, I had them installed correctly and using Aquarium Co-Op dual outlet air pump.

Good price and quality work s as designed

Awesome easy to install 👍