Although this is an inexpensive product, it seems to be effective and well made. I have been using these for a couple months now and have determined that I can trust them. I have tested them by attempting to get back-flow. I have tried to induce a siphon similar to what would happen with a pump failure and found no leaks. With pressure far beyond normal siphon pressure they hold tight. Also important, they do not induce abnormal pressure in the forward direction. I trust these valves.
I have ordered these several times and they always work and are a quality product. Thanks!
I have had no problems with this check valve except when i put it on backwards ;) another great product from aquarium co-op.
Low back pressure. Good check valve.
I never leave reviews, but this needs one. Set up co2, needed a check valve, and this was the first place I came too. Apparently they last "3-5 years", maybe if used in an air pump. I bought 5 of these just in case. First one leaked and didn't let co2 pass through. I hot glued the 2nd one at the seams and it didn't leak, but gas still didn't pass through. Waste of 15$.