Marina Elite Plastic Check Valve

One worked fine, the other did not, tried it both directions but no luck, i checked the valve andIt seem it be clogged blew thru it and it works, not as strong as the other one was going to return, but to much of a hassle.

If you are using an air stone in your aquarium, and you should be, a check valve is a must have!!! If your air pump is below your water level a siphon action can occur, if this happen you are in for a big mess and a big problem for your fish. This simple and inexpensive device can prevent this from happening.

The check valve works without impeding the air flow. Great design! Nice price!

Perfect and looks to be a better quality then others!!!

When they work they are good or when they arrive undamaged. I had to return 2, 1 just didn't work, could not blow air through it, the replacement arrived damaged from shipping.

Came with small crack but still works as it should.

I used this for CO2 tank and it worked ok, but did allow water to backup into my bubble counter. I probably shouldn't have used a plastic one for CO2, but for me it wasn't completely reliable. Even with this, it was better than nothing and worked well enough until I found a better alternative.

Perfect valve to have between my CO2 canister and ladder. Inexpensive and doesn't appear to restrict flow. Lots of bubbles. (Even though the Hagen Nutrafin CO2 system does not require you to use a check valve, it's good to have one in place if you're canister isn't at tank level).

I would give this product a full 5 stars if it was slightly cheaper based on its function. Yes, it will save your air pump in emergency situations, but I've never had a power outage on any of my aquariums before so I can't personally vouch for its abilities but hopefully, it will save my equipment when the time comes. If you have more than 5-10 personal aquariums/fish tanks, I would recommend trying to make some check valves yourself using simple materials and an online tutorial or video.

Works great! No instructions included just a confusing low quality black and white drawing that doesn't match the actual product very well.At first it didn't work, than I realized that I had it backwards. Flipped it and it was fine. Tested if water will go through it now that it's installed properly. It won't.

Install it on my CO2 system. Did not stop de water to go back. I have to rearrange my tubing to get gravity on my side and reduce the amount of work that valve had to do. Now it's seems to work but I cannot touch it, I'm to afraid it will stop working again. I would not recommend that product.

Love the spring design as it stressed out my pump way less and keep my bedroom free from backed upped water. I use it on a pump that has an air splitter for two sponge filters, and there is almost minimal resistance to the pumps in terms of proper flow and no straining sounds from the pump (which is evidenced by more pump noise).Does exactly what it is supposed to do with beautiful simplicity. Remember the KISS rule folks.

This check valve uses a spring mechanism which provides less air flow resistance than the pinch style check valve. Less air flow resistance means a lower rate of wear on your air pump. If the spring were to fail (a broken spring), water back flow will close the valve - pretty simple design.Great job Marina.