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Check Valve Placement?

Discussion in 'Plant CO2' started by Nick72, May 21, 2019.

  1. Nick72 Valued Member Member

    I'm going to be installing a pressurised CO2 Injection kit - C02 Art Pro Elite.

    I'm happy I've read up / watched YouTube enough to install the system.

    The last question I have is on the Check Valve/s.

    The bubble counter on this system comes with a built in check valve - so that's immediately after the needle valve and before the bubble counter (essentially at the regulator) - should I install another check valve further up the line - perhaps at the diffuser or as the C02 line comes out of the aquarium?

  2. TheBettaSushi Well Known Member Member

    I just saw a video from aquarium co-op about this. It was suggested to place a check valve right where the diffuser tubing meets the top of the aquarium to prevent the diffuser from sucking up water through the tube. The closer the check valve is to the diffuser, the easier it will be to get rid of backed up water in the tube. I’m assuming you need two check valves. One for the diffuser and one for the bubble counter as they’re two separate lines?
    Last edited: May 21, 2019
  3. aniroc Well Known Member Member

    " to prevent the diffuser from sucking up water through the tube" Is that what what the check valve is all about?
  4. TheBettaSushi Well Known Member Member

    A check valve is needed to prevent back flow of aquarium water in case something happens... for instance, a pump or co2 that becomes faulty or if the electricity goes out, it can cause water to siphon out of the aquarium and into the co2 tanks or air pumps. It’s extremely important to use a check valve to prevent this from happening. The only time it isn’t needed is if an air pump or co2 cylinder is placed above the tank where tubing goes straight down into a tank. Most of us usually put that type of equipment below the tank so it’s necessary to have a check valve to prevent water damage to our equipment.
  5. Nick72 Valued Member Member

    Hi @TheBettaSushi - I'll only have one line, regulator to check valve, to bubble counter, to diffuser.

    Just with the bubble counter being attached to the regulator I was concerned that I will have up to 2 meters of C02 line in which water could flow from the diffuser back to the bubble counter.

    This might be fine? But I think I'm supposed to be pushing C02 through the line through air not through water, IDK.

    Seems to make sense to have a check valve before the bubble counter to protect the regulator, and also near the diffuser to keep the C02 line clear.

    This would also add one level of redundancy to the system. So I think this is the way I will go.

    Only thing holding me back is that I saw a thread somewhere where a guy was having trouble getting C02 to pass through two check valves.

    Sounds like the video you watched was going the same way - thanks for the feedback.
  6. TheBettaSushi Well Known Member Member

    You’re right... the co2 art is only one line... however, I think that the check valve you have in the bubble counter is only for the bubble counter to prevent whatever water that is in there to not leak into the co2 cylinder. I’m assuming it would help the diffuser not siphon out water as well but I can’t be too sure so I’d use a stainless steel check valve right next to the diffuser.

    Here is a reddit thread (photo) of a CO2Art regulator being used with a bubble counter and a stainless steel check valve. This is connected to an in-line but it’s basically the same thing as using a diffuser inside the tank... the in-line is just connected to the canister filter instead of being inside the tank. Whatever goes into the tank should have something to prevent it from coming back out, in this case co2 and aquarium water.


    And yes, you should be pushing co2 through air in the line... not water.